Issued by the Director General of Telecommunications

Contents

Introduction

General Conventions

1: Rights, responsibilities and the review procedure
2: Applying for numbers or codes
3: Reserving numbers or codes
4: Considering applications
5: Conditions placed on allocations
6: Re-allocating and withdrawing numbers or codes
7: Requirement to notify others
8: Specified Numbering Scheme records

Conventions for numbers and codes for the public switched telephony network

A1: Structure of the Scheme
A2: Standards and standard presentation
A3: Geographic numbering ranges (01,02 & 03)
A4: Corporate numbering (05)
A5: ‘Find-me-anywhere’ services (07)
A6: Special services (08)
A7: Premium Rate Services (090/ 091)
A8: Broadband services (092+)
A9: Access Codes and Short Codes

Conventions for other codes and numbers

B1: Inbound and Internal Routing Codes
B2: Data Network Numbers and Codes
B3: Telex numbering

Glossary

Introduction

1 The Numbering Conventions for the United Kingdom (the ‘Conventions’) are a set of principles and rules relating to the use and management of numbers from the Specified Numbering Scheme (the ‘Scheme’). The Conventions are not intended to be used as a guide for consumers to any aspect of numbering policy or management.

2 The Conventions also govern the specification and application of the Scheme and licensees’ Numbering Plans. It is a breach of the Numbering Arrangements Condition, contained in a licence granted to an operator under Section 7 of the Telecommunications Act 1984, for an operator to not have a Numbering Plan, or to have a Numbering Plan that does not accord with these Conventions. Oftel uses the procedures set out in the Telecommunications Act 1984 to enforce any breach of a licence condition.

3 The Conventions are revised from time to time by the Director General of Telecommunications (the ‘Director’) after consultation with relevant licensees and interested parties. The first, second and third issues of the Conventions were published in June 1994, April 1997 and November 2001, respectively. This fourth issue takes into account arrangements for the implementation of the allocation procedure for codes for Directory Enquiry (DQ) services.

4 Comments or queries regarding the Conventions should be directed to:

The Numbering Unit
Oftel
50 Ludgate Hill
London EC4M 7JJ

E-mail: numbers.oftel@gtnet.gov.uk

5 Numbering information appears on Oftel’s website: www.oftel.gov.uk/ind_info/index.htm.

General Conventions

1: Rights, responsibilities and the review procedure

Oftel’s guiding principles

1.1 The Office of Telecommunications (Oftel) is responsible for managing the Scheme and issuing the Conventions. In addition, Oftel is responsible for developing numbering strategy in the national interest and developing the Scheme. Numbers and codes are a national resource and the following guiding principles will be taken into account by Oftel when allocating, reserving or managing numbers:

a) Oftel will manage the Scheme to ensure that there are sufficient numbers available to meet all reasonable demands that end users, operators and service providers might have.

b) The Scheme will, where applicable, be compatible with relevant European and international agreements, standards and recommendations.

c) The Scheme will, wherever possible, seek to ensure that numbers of different types give a broad indication of service and/or tariff.

d). Oftel will ensure that costs or inconvenience to consumers, operators and service providers are objectively justified, and kept to the minimum consistent with meeting demands for numbers and sound management of the Scheme.

e). Oftel will allocate or reserve numbers in a fair and equitable manner, normally to the first operator that requests the block or code (ie on a ‘first come first served’ basis). Oftel will only allocate or reserve numbering capacity to operators who meet the eligibility criteria set out in Convention 2.

f) Oftel will take into account the need to anticipate growth and innovative services in demand for telecommunications services and, when allocating numbers, the need to conserve numbering capacity in ranges identified as having a number shortage (eg, Conservation Areas, a list of which is placed on the Oftel website). In particular, the utilisation of previous numbering allocations, including any numbers made available for porting, will be taken into account when considering new requests for number allocations.

Operators’ responsibilities

1.2 Operators who have received allocations of numbers or codes shall act in accordance with the following principles:

a) Operators shall adopt a Numbering Plan, for such numbers or codes as are allocated to it, in accordance with the Conventions

b) Operators shall be efficient in their use of numbers

c) Operators shall not brand numbers, nor associate a number range with a given operator.

Reviews of the Conventions and the Scheme

1.3 Oftel may from time to time review the Conventions and/or the Scheme upon its own initiative, or upon a request in writing by any operator, service provider, user or other interested party.

1.4 The Director may from time to time amend or withdraw in full or in part the Scheme and/or a Convention already published, or publish additional Conventions. This would take place only after consulting with relevant licensees, interested parties who are members of the Telecommunications Numbering and Addressing Body (TNAB) and, if the Director considers it appropriate, end users.

1.5 The normal consultation period will be three months. However, in exceptional circumstances, a shorter consultation period of not less than 28 calendar days may be appropriate.

1.6 Licensed operators will not be required to comply with any such amendment or withdrawal, unless they have been given a reasonable period of notice, such notice not being less than three months.

Structure of the Conventions

1.7 These Conventions are structured in two parts. The first part (Conventions 1 to 8) sets out the general rules or principles concerning the procedures for applications, reservations, withdrawals and other operations of the Scheme from both Oftel and recipients’ points of view. The second part (Conventions A1 to A9 and Conventions B1 to B10) sets out specific rules relating to numbers or codes within the public switched network or other parts of the Scheme.

1.8 This structure is for presentational purposes only and shall not affect the status of any of the individual Conventions, whether they are placed in the first or second part of these Conventions.

2: Applying for numbers or codes

Criteria for the eligibility of applicants for number allocations and reservations

2.1 All operators providing publicly available telecommunications services and running a telecommunication system under a licence granted under Section 7 of the Telecommunications Act 1984, whether that is an individual or a class licence, containing Numbering Arrangements Condition, are eligible to apply for allocations and reservations of numbering capacity.

2.2 Other persons who may require an allocation of numbering capacity, but who are not eligible under Convention 2.1 above, should seek a sub-allocation from an eligible operator (as defined in Convention 2.1 above). Sub-allocations should be fairly and reasonably available from such operators. However, Oftel is prepared, at its discretion, to consider reserving or allocating numbers or codes to systemless service providers in demonstrably exceptional circumstances (eg, where a systemless service provider is in the process of setting up a system).

Information to be supplied by an applicant for a numbering allocation and/ or reservation

2.3 When applying for an allocation or reservation of numbering capacity, the applicant shall provide the following information to Oftel’s Numbering Unit on an appropriate application form (available from Oftel’s Numbering Unit):

a) Name and contact details of the applicant.

b) Where a person submits an application form on behalf of the applicant, a signed and dated letter of authorisation shall accompany it from that applicant.

c) Details of the Telecommunications Act licence under which the applicant intends to operate the numbering capacity sought and of the system being operated.

d) Details of any existing ranges held that are relevant to that application.

e) Details of the operator’s interconnection and number portability arrangements.

f) A preferred numbering code and/or block and, where appropriate, second and third preferences should be indicated.

g) Where relevant, details of the type of telecommunications service intended on the range and the proposed tariff rate of the service.

h) Details of the applicant’s utilisation of existing number allocations. For example:

• Numbers in service allocated to end users;
• Capacity not in use but contracted for (geographic numbering only);
• Numbers set aside for geographic growth or customer orders; and
• A forecast of expected utilisation over a specified period.

i) Any other information that the applicant considers necessary or appropriate to justify the application.

2.4 In addition, applicants shall provide to Oftel any other information, judged by Oftel to be relevant to the application, and the supply of which does not place an undue burden on the applicant. This may include a brief description of the applicant’s technical and operational system configuration.

Timing of applications

2.5 Applications for numbering allocations should not, in general, be made more than six months prior to the planned in-service date.

3: Reserving numbers or codes

Making reservations

3.1 In addition to allocating numbering capacity, Oftel may, at its discretion, agree to reserve it. Reservations are appropriate where:

a) an applicant does not want to be identified;

b) the reason for the application should not be divulged prior to an application for the allocation; or

c) a customer order has not been finalised.

3.2 A reservation may be made:

a) in anticipation of an application being made for numbering capacity in accordance with a three year rolling forecast provided by licensees entitled to apply for an allocation; or

b) against a specific request submitted by any person eligible to receive allocations (for example, for the expansion or growth of existing services or for the introduction of new services).

3.3 An application for a reservation shall be made to Oftel’s Numbering Unit in accordance with Convention 2. Applications for reservations will be treated in confidence, unless the applicant requests otherwise.

Limitations

3.4 Wherever possible, Oftel will endeavour to convert a reservation into an allocation upon request. However, it should be noted that a reservation does not automatically entitle an applicant to activate the capacity. Nor, where numbering capacity is reserved, is there any guarantee that a corresponding allocation will subsequently be made. Reservations will be time-limited and the limit for reservations will normally be three months. Reservations may be renewable on request to Oftel.

Cancellation

3.5 Once a reservation has been made, that numbering capacity will be unavailable for allocation, except for the purpose and to the organisation for which the reservation was made. However, a reservation will automatically be cancelled if:

a) the time limit has expired;

b) the applicant withdraws the reservation; or

c) Oftel and the applicant agree a substitute reservation or allocation.

Competing requests

3.6 Where available number ranges are limited, and several operators have requested the same number block, Oftel may reserve the block for more than one operator, but will allocate it to the first operator who provides Oftel with firm evidence of a customer order.

4: Considering applications

4.1 When making number allocations or reservations within the Scheme, Oftel will take into account:

a) the guiding principles set out in Convention 1.1;

b) the provisions of the Numbering Arrangements Condition and, where appropriate, any other relevant licence conditions;

c) the views of the applicant and other interested parties (through consultation, where appropriate); and

d) any other matters that Oftel deems relevant (eg, any requirement to open a new range or make changes to the Scheme in order to allocate the required numbers or codes).

New number ranges or changes to the Scheme

4.2 Before opening any new ranges, or significant parts of ranges, Oftel will publish a notification in the Numbering Bulletin. Oftel will give at least 28 calendar days’ notice of the opening of any new ranges or significant parts of ranges. Oftel will also specify a date for the initial receipt of applications for those ranges and, prior to that date, no applications will be accepted.

4.3 Oftel will notify the ITU Telecommunications Standardisation Sector (‘ITU-T’) of changes to the Scheme and ensure that the correct notification is given in the ITU-T Operational Bulletin. Where Oftel considers it appropriate, it will also notify other overseas administrations, such as those that do not subscribe to the ITU-T Operational Bulletin.

Number portability

4.4 Oftel may take into account how the applicant intends to provide portability for relevant numbers when considering applications.

Timescale for handling applications for numbering capacity

4.5 Oftel will use all reasonable endeavours to make an allocation or reservation in accordance with the Conventions, in response to applications for numbering capacity, within a period of twenty-eight calendar days following receipt of an application that contains all of the information required by Convention 2.

4.6 The period referred to in Convention 4.5 may be exceeded where:

a) additional information is required from the applicant;

b) a period of consultation is necessary, as initiated by Oftel;

c) there are significant issues relating to the application that cannot be reasonably handled within that period;

d) evidence is required that an applicant is running a system licensed under Section 7 of the Telecommunications Act 1984; or

e) Oftel considers that an alternative period of time is justified.

4.7 Where Oftel considers that an exception to the normal period is required, then it will inform the applicant in writing of its reasons and of the revised period. Generally, this period will not exceed ninety calendar days from receipt of an application that contains all of the information required by Convention 2.

Refusal of applications for numbering capacity

4.8 Oftel may refuse an application for an allocation or reservation of numbering capacity. Alternatively, Oftel may not grant the application in full, or may attach specific conditions to the allocation which are consistent with the Conventions and relate to the use and management of the numbering capacity allocated. Such specific conditions will be set out in the letter that accompanies the Allocation Certificate.

4.9 In the event of a refusal, whether in part or in full, or where specific conditions are attached, Oftel will inform the applicant, in writing, of its reasons.

4.10 Oftel may, following consultation with the applicant, make an alternative allocation that has the potential to satisfy the applicant’s requirements without conflicting with the criteria that caused the original application to be refused.

4.11 Where Oftel refuses an application, either in part or in full, or attaches specific conditions to the allocation, the applicant may write to the Director disputing the reasons given by Oftel for its decision or giving further information for consideration regarding the application. The Director will then consider the request and respond to the applicant within 28 calendar days.

  5: Conditions placed on allocations

General conditions

5.1 In addition to any specific conditions that may apply (see Convention 4.8), the following general conditions, relating to the use and management of numbering capacity, apply to all allocations made by Oftel:

a) the allocation shall be used for the purpose specified in the application (eg, including any classification by type or tariff as set out in the Scheme);

b) the person originally allocated numbers shall be responsible for them. This does not prevent that recipient sub-allocating numbers, provided that the sub-allocation is still for the use specified in the original application and in accordance with the Conventions;

c) the holder of the allocation shall maintain a record of the percentage of numbers in use;

d) the holder of the allocation shall maintain a record of numbers that have been ported to another operator (‘ported numbers’);

e) holders of numbering capacity shall not, unless the Director consents otherwise, charge any person for a number allocated to him (other than a coveted number allocated to a person who is not a public telecommunications operator at the request of such a person); and

f) an operator shall not use numbers from the Scheme other than those allocated by Oftel.

Conditional allocations – codes

5.2 Oftel may allocate a code to an operator on the condition that it is used exclusively for traffic to and from a specified third party. In addition, it may be allocated on the condition that the code shall be capable of being transferred to that third party if, in due course, that third party becomes eligible to receive allocations of codes in its own right by satisfying the eligibility criteria in Convention 2.1 above.

Changes to allocations

5.3 Those who have been allocated numbering capacity are required to apply to Oftel to make any changes:

a) to the ownership of the block or code;

b) to the purpose or use of the numbering allocation; or

c) which relate to conditions of use placed on the allocation.

The audit process

5.4 Each holder of an allocation shall submit to Oftel an ‘Annual Numbering Return’. The Annual Numbering Return shall refer to information at the calendar year end and shall be submitted to Oftel as requested, but usually within one month of the end of that year.

5.5 The following information shall be provided in the Annual Numbering Return for each allocation:

a) the current use of the allocation;

b) numbers in service allocated to end users;

c) details of numbers set aside for planned growth, customer orders or other usage, with explanations;

d) blocks of numbers allocated to any person for purposes other than end use; and

e) the proportion of numbers ported, at the request of end users, to another operator, including those ported before allocation.

5.6 Each Annual Numbering Return shall also provide:

a) a three year forecast of demand within significant ranges, as specified by Oftel;

b) the justification for continuing reservation by the operator of numbering capacity; and

c) any other information requested by Oftel.

5.7 This information shall be supplied in a format specified by Oftel. Oftel will not require information where the collection or analysis of the information would place an undue burden on the organisation submitting the Annual Numbering Return.

Annual numbering report

5.8 Oftel will prepare an annual numbering report on the organisation and use of the Scheme for publication each year, usually in April.

  6: Re-allocating and withdrawing numbers or codes

Reallocation

6.1 If a substantial proportion of numbers from an allocation has been transferred (eg, sub-allocated or ported) to another operator, Oftel may, with the agreement of the operators concerned, re-allocate the number block to the operator who has most users in the block. Oftel will re-allocate number blocks or codes only when it has received the written consent of both the existing allocatee and the intended new allocatee.

Withdrawal

6.2 Oftel will withdraw capacity that it has allocated, or part of such capacity, if its continued use or allocation is not in compliance with:

a) the Conventions;

b) the Scheme; or

c) any specific conditions of the allocation.

6.3 Withdrawal of an in-service numbering range, which has been allocated by Oftel, can be made only after Oftel has consulted with interested parties for a period of not less than twenty-eight calendar days. It will be subject to a period of notice of not less than three months following that consultation.

6.4 If an allocation or part of an allocation is not brought into service within six months, it may be withdrawn, after consultation with such interested parties and for such period as specified in Convention 6.3 above. Such withdrawal will be subject to a period of notice of not less than three months following that consultation.

7: Requirement to notify others

7.1 When activating a number allocation, it is the responsibility of the holder of the allocation to negotiate with, and to notify, relevant United Kingdom operators and, where appropriate, overseas authorities. This will be done within a timescale agreed between the operators and/or organisations.

7.2 Those who have been allocated numbering capacity are required to advise Oftel, on an ongoing basis, of the contact in their organisations to whom notifications of the dates for activation of the allocated codes and number blocks should be sent.

7.3 Oftel will maintain a list of such contacts and will make it available on request to all organisations listed on it, and others who, in Oftel’s opinion, have need of that information.

8: Specified numbering scheme records

8.1 Oftel will maintain comprehensive records of the status of all number ranges, codes and blocks of numbers comprising the Scheme. The full Scheme will be set out in a list (the Specified Numbering Scheme List or ‘SNS List’) kept by Oftel and made available on Oftel’s website. Oftel will endeavour to update the SNS List on Oftel’s website on a weekly basis.

8.2 Where available and not commercially sensitive, details of the operator’s plans for reserved numbering will be included on the SNS List on Oftel’s website. However, those requiring further details of reservations are advised to contact the person for whom the code or block of numbers has been reserved.

Publication of changes

8.3 In addition to updating the Scheme at the earliest opportunity, Oftel will publish confirmations of allocations, reservations or withdrawals, setting out the number range(s) being allocated, reserved or withdrawn, the person to whom the allocation has been made or from whom it has been withdrawn, the action date, and the case number.

Status indicators

8.4 Oftel will structure the Scheme so that all numbers or codes will fall into one of two categories: namely, either designated or not designated. Designated numbers or codes are those set aside within the scheme for particular usage: eg, geographic, ‘Find–me-anywhere’, premium rate, etc, and also, within geographic ranges, what area the code is designated for. Designation is no indication as to the availability or otherwise of a number or code. Those parts of the Scheme that are not designated, have not been set aside for a use specified in Convention A1, and are therefore not available for allocation or reservation.

8.5 Codes or numbers that have been designated will, unless this is with reference to a Type A or a Type C Access Code (see Convention A9), have one of the following, more specific, status indicators (listed in alphabetical order) within the Scheme:

‘Allocated’ – indicates codes or numbers that have been allocated to a person whose name will be listed alongside. While the majority of codes and number blocks shown as ‘Allocated’ may also be in public service, these records will not contain information about in-service dates. In addition, allocations will not appear with full details on the SNS List while an applicant maintains a requirement to protect commercially sensitive information prior to the opening of service.

‘Allocated for Migration Only’ – indicates that the code or block has been allocated to a listed person for the express purpose of managing a migration from one range to another. This may be a temporary allocation and, after a suitable, specified time, and the meeting of allocation criteria, Oftel may determine that the block could be used for new business and its status changed accordingly.

‘Free’ – indicates that this code or block is available for allocation or reservation. Applicants should note that a number block shown as ‘Free’ could have already been requested by another operator between the time of the last update of the list and the time of applying for the number block.

‘Free for X’ – indicates numbering ranges which are free only for specific purposes, eg, ‘Free for National Dialling Only’, which is used to show where numbers are available only for use where a geographic code will always be added (see Convention A3.15 for further details), and ‘Free for New 100,000 Block Only’ which indicates where number ranges are not normally available for allocation or reservation while numbers are still ‘Free’ in previously opened ranges within that geographic code area (see Convention A3.12 for further details).

‘Protected’ – indicates where a number block is protected until further notice or, where a date is shown, until that date. Numbers are protected, eg, for future planning purposes or to avoid temporary or permanent dialling problems.

‘Reserved’ – indicates a provisional allocation, subject to confirmation by the applicant and/or Oftel. The applicant’s name will not normally appear alongside the reservation to ensure commercial confidentiality.

Conventions for numbers and codes for the public switched telephony network

A1: structure of the Scheme

A1.2 The structure of the Scheme is as follows (with the national prefix digit (‘0’) and initial Scheme (‘S’) digit identifying the range):

00	The international prefix code, used to access international dialling.
01	The Geographic Numbering Range with five, six or seven digit local numbers (see Convention A3).
02	The Geographic Numbering Range with eight digit local numbers (see Convention A3).
03	Future Geographic Numbering Range (see Convention A3).
04	Future use.
05	Corporate Numbering (see Convention A4).
06	Future use.
07	‘Find-me-anywhere’ Range for Personal, Mobile and Paging services (see Convention A5).
08	Special Services (see Convention A6).
09	Premium Rate Numbering and Broadband Services (see Conventions A7 and A8).

A1.3 Since the numbering capacity associated with a range may exceed the potential demand for the usage identified in Convention A1.2 above, allocations will be made from particular A digits, leaving other values of A digit free for future allocation to the given usage or for alternative designation. Similarly, capacity will be conserved by care in the allocation of B, C and D digits to avoid large blocks of numbers being sterilised.

A2: Standards and standard presentation

A2.1 So far as it is practicable, the Scheme will conform to the relevant international standards. In particular, attention is drawn to the following ITU-T Recommendations, or their functional successors:

‘E.123’ –	Standard notation for national and international telephone numbers (see Convention A2.3 to A2.9 below).
‘E.161’ –	Arrangements of figures, letters and symbols on telephones and other devices that can be used for gaining access to a telephone network.
‘E.164’ –	The international public telecommunications numbering plan.
‘E.166’ –	Numbering plan for inter-working the E.164 and X.121 number plans.
‘X.121’ –	International numbering plan for public data networks.

A2.2 ITU-T Recommendations E.169.2, E.169.3, E.175, E.191 and E.195 describe the role of the ITU-T in introducing universal services. The allocation of numbers for such services (eg, International Freephone 00800) is the responsibility of the ITU-T.

Country code

A2.3 The country code allocated by the ITU-T to the United Kingdom is 44. This code follows the international dialling prefix on calls made from outside the United Kingdom, and should be followed by the NSN of the destination within the United Kingdom, excluding the national dialling prefix, ‘0’. The country code ‘44’ is also used by the Channel Islands and the Isle of Man.

Maximum number of digits

A2.4 Particular attention is drawn to ITU-T Recommendation E.164 which states that the maximum number of digits that a national system is expected to handle on an outgoing international call is fifteen (15) (excluding the international dialling prefix).

Alphanumeric arrangements

A2.5 The Scheme will use the decimal character set 0-9 for all number allocations. Letters and other non-decimal characters will not form any part of the United Kingdom’s NSN. The use of alphanumeric keypads is recommended for telecommunication terminals to facilitate a harmonised means of transfer of information within those countries who, like the United Kingdom, are members of the European Conference of Posts and Telecommunications (‘CEPT’). In the event that an alphanumeric arrangement is used which exceeds the number length of the range dialled, this confers no right to the longer sequence, nor any guarantee that it will work.

A2.6 The use of the following set of keypad arrangement is strongly recommended, in line with ITU-T Recommendation E.161 Option A:

Prefix ‘0’

A2.7 The prefix ‘0’ will be used for all calls within the United Kingdom other than for some locally dialled calls and short access codes, including 999. For calls within the United Kingdom, the digits of a NSN will follow this prefix. Operators are expected to engineer their systems to accept nationally dialled calls that could otherwise have been made using local dialling. On networks where only full national dialling is provided, only the following initial digits will be used for any public service (except where Oftel has designated other digits):

0	(national prefix);
1	(Access codes – see Convention A11); and
999

Prefix ‘00’

A2.8 The international prefix ‘00’ is used for international dialling from the United Kingdom. The digits of the country code and the NSN will follow this prefix. This also applies to ISDN data calls.

Consistency of format

A2.9 Numbers can be presented in whatever way operators or users wish, so long as there is no intention to deceive or confuse. However, considerable benefit can be obtained from consistent forms of number presentation. The recommended formats for ten-digit NSNs under the Scheme are as follows (In these examples of best practice, the brackets are used to indicate that the digits within are not required for local dialling):

Geographic numbering ranges:

(01AB) CDE FGHI - 01 range with seven-digit local dialling.

(01ABC) DEFGHI - 01 range with six-digit local dialling.

(01ABCD) EFGHI - 01 range with five-digit local dialling.

(02A) BCDE FGHI - 02 range with eight-digit local dialling.

International format:

+44 1AB CDE FGHI

+44 1ABC DEFGHI

+44 1ABCD EFGHI

+44 2A BCDE FGHI

Non geographic numbering ranges:

A2.10 Benefit can also be obtained from consistent forms of non-geographic number presentation (ie where the ‘S’ Digit is a 5, 7, 8 or 9). The recommended formats for these ten-digit NSNs are as follows:

0SAB CDEFGHI

0SABC DEFGHI

  A3: Geographic Numbering Ranges (01, 02 and 03)

A3.1 In the Scheme, the 01, 02 and 03 ranges have been designated as the Geographic Numbering Ranges (‘GNR’), although the 03 range is currently protected for future use. In particular, the 02 range has been assigned for use to overcome the exhaustion of existing 01 area codes. The 02 codes will be allocated in the form 02A followed by B, BC or BCD digits to replace directly the existing 01 code. The B, BC or BCD digits will be added to the existing local number to form a new eight-digit local number. In this way, the integrity of the existing geographic structure will be maintained, while at the same time setting out the basis for its future evolution.

A3.2 Oftel will give at least two years’ notice of any code change.

A3.3 In deciding how future 02 or 03 codes should be used, Oftel will take into account the following factors:

a) areas likely to be affected by number shortages;

b) anticipated growth in demand for numbers;

c) demographic and business trends;

d) the existence of communities of interest;

e) the need for efficient utilisation of numbering resources; and/or

f) any representations received on behalf of local communities.

A3.4 To ease the migration by end users to new codes and numbers, operators shall ensure that the following measures are in place wherever possible:

a) there must be adequate notification and publicity to end users prior to a change;

b) there must be a period of parallel running when numbers to the old and new codes are available; and

c) there is a changed number announcement after the completion of the change.

A3.5 An indication of the areas served by each of the codes in the GNR is given in the Scheme. Oftel will advise on the procedure for licensed operators on how to obtain a map of the United Kingdom showing the areas and codes used. Oftel will ensure that more precise details of the boundaries can be obtained, when necessary.

A3.6 Calls anywhere within the GNR may be made using full national dialling, including the national prefix (0). Additionally, operators will allow callers having the same National Destination Code as the called party to use only the Subscriber Number.

A3.7 The boundaries of the areas covered by the GNR will be material to the operators offering services in or around those areas. Oftel may make changes to the boundaries following consultation with relevant interested parties.

Conservation measures

A3.8 Geographic numbers will normally be allocated to applicants in blocks of 10,000 with DE digits (see Convention A2.9) in the appropriate area code range. However, in those areas where conservation measures have been announced, numbers may be allocated in blocks of 1,000. Accordingly, conservation measures will not only enable Oftel to delay implementing code changes, but may remove the need for some code changes altogether.

A3.9 Oftel will publish and revise as appropriate a list of Conservation Areas. The assessment of what constitutes a Conservation Area takes into account confidential audit returns, actual allocations over recent years, and Oftel’s knowledge of local factors.

A3.10 Conservation Areas will be separated into two types:

a) Conservation Areas where numbers will be allocated in units of 1,000 (‘Type A Conservation areas’); and

b) Conservation Areas where numbers will be allocated in units of 10,000 (‘Type B Conservation Areas’).

A3.11 Type A Conservation Areas are those which Oftel believes are within two years of having less than ten spare 10,000 number blocks available. In addition to allocating new blocks in those areas in units of 1,000 numbers, Oftel may, following at least six months written notice to operators, withdraw such 10,000 number blocks as have been previously allocated to them, and reissue to them an appropriate number of 1,000 number blocks from that 10,000 number block. An appropriate number in this context will be sufficient to cover existing usage and reasonable future utilisation.

A3.12 Allocations in Type B Conservation Areas shall be conditional upon planned usage of numbers in units of 1,000 at a time, and, should the area become a Type A Conservation Area, Oftel may withdraw and reissue numbers in accordance with Convention A3.11.

A3.13 Additionally, in order to conserve numbers, Oftel will not normally open a new 100,000 range while numbers are still free in previously opened ranges within that code area.

A3.14 Operators licensed to offer service in more than one local geographic code area must seek an allocation of number blocks for each of the relevant codes in those areas in which they wish to provide service in accordance with the GNR.

National dialling only

A3.16 Certain GNRs are shown as ‘Free for National Dialling Only’, where full national dialling is required. These numbers cannot be used for locally diallable Subscriber Numbers.

A3.17 However, to promote greater use of the numbering capacity, Oftel will encourage operators to make maximum use of these ranges for services in circumstances where local dialling is not required. Such services include, but are not limited to, number translation, outgoing-only traffic, and voice mailboxes. Where an outgoing-only number is used a presentation number must appear for caller-line identification purposes. In the event of a code change to eight-digit numbering, these ranges would become usable and Oftel would normally offer replacement ranges from the new pool of ‘National Dialling Only’ blocks. Operators will be required to migrate to these new ranges by the end of parallel running.

  A4: Corporate Numbering (05)

A4.1 The 05 range has been designated for Corporate Numbering or Freephone 0500. Corporate number services will be provided from the Scheme.

A5: ‘Find-me-anywhere’ services (07)

A5.1 The 07 range has been designated for ‘Find-me-anywhere’ services. These are services that enable end users to be contacted, whatever their location, where the call charge is not distance dependent. Mobile, Personal Numbering and paging services shall only use the respective 07 range designated below:

070	Personal Numbering Services.
076	Paging Services.
077	Mobile Services.
078	Mobile Services.
079	Mobile Services.

Personal numbering

A5.2 Oftel may allocate 070 numbers in 10,000 or 100,000 number blocks at the applicant’s request and where it considers this to be appropriate, taking into account:

a) demand forecasts;

b) previous allocations and reservations by the applicant and others offering similar services; and

c) the need to conserve capacity.

A5.3 In particular, the only services allowed to be used for the 070 range shall be Personal Numbering Services, which enable end users to be called using a single telephone number and to receive those calls at virtually any telephone number, including mobile numbers. The range of 070 numbers is suitable for end users who habitually move location.

A5.4 For the avoidance of any doubt, the 070 range shall not be used for Premium Rate Services.

A5.5 Any person to whom Oftel has allocated 070 numbers (the "original 070 allocatee") shall not share with end users any revenue obtained from providing a Personal Numbering Service. Where the original 070 allocatee sub-allocates 070 numbers to persons other than end users, such as to a provider of Personal Numbering Services or another operator, that original 070 allocatee shall, prior to making such a sub-allocation (and without prejudice to the generality of his obligations under Convention 5.1), ensure that such persons undertake to procure that revenue obtained from providing a Personal Numbering Service is not shared with end users.

Paging and mobile services

A5.6 Oftel will allocate paging and mobile service numbers in blocks of 100,000.

    A6: Special Services (08)

A6.1 The 08 range has been designated exclusively for Special Services. These are services paid for through the telephone bill of a subscriber, and charged at special rates. The cost of the call to services in the 08 range shall be:

a) paid by the called party (eg, 080 Freephone numbers);

b) shared between the caller and the called party (eg, 0845 local rate numbers); or

c) paid wholly by the caller (eg, 0870 national rate numbers).

A6.2 Operators and service providers shall offer services at the stated tariffs, eg, the tariff for an 0870 national rate call shall be no higher than the tariff for standard geographic national calls in the 01, 02 and 03 ranges.

A6.3 Allocation of numbering in the 08 range will normally be in blocks of 10,000, whilst tariffing will be in blocks of 100,000. An exception will be certain recycled mixed length 0800 blocks that are allocated in blocks of 1,000 numbers (such blocks are marked accordingly in the Scheme). The number length will normally be ten-digits (excluding the national prefix ‘0’), except, inter alia, for numbers in the closed nine-digit 0800 (and 0500) number ranges. Any variation from ten-digits must be with Oftel’s approval and will be shown in the Scheme.

A6.4 In order to allow meaningful tariff information, codes will be allocated with A, and where relevant, with B, digits having the following significance:

080 -	No charge to caller*
082 -	Internet for Schools
0844 -	Up to 5ppm, set by terminating operator**
0845 -	Originating operator’s ‘Local Rate’**
0870 -	Originating operator’s ‘National Rate’**
0871 -	Up to 10ppm, set by terminating operator**

* Except on certain networks where charges shall be notified to callers at the start of the call

** Tariffs are inclusive of VAT

A6.5 Oftel may designate further sub-ranges for specific services/tariffs from time to time. Information notes published by Oftel in the Numbering Bulletin will set out any new sub-ranges.

    A7: Premium Rate Services (090 and 091)

A7.1 The 09 range has been designated for Premium Rate Services, both with and without content, and broadband services. In order to preserve capacity and to provide service meaning to callers, codes will be allocated with A-digits having the following significance:

090	Premium Rate Content Services.
091	Premium Rate Non-Content Services.
092 – 099	Broadband services.

Premium Rate Services

A7.2 Premium Rate Services are normally expected to have the following characteristics:

a) they are paid for through the telephone bill of a subscriber;

b) they are charged at rates above Special Services in the 08 ranges;

c) the revenue for the call, which comprises the price of the telephone call plus the content, product or service, is shared between the operator and the provider of the service whether directly or indirectly; and

d) they are not ‘Find-me-anywhere’ services.

A7.3 Premium Rate Content Services in the 090 sub-range are those services which, apart from having the characteristics in Convention A7.2, include a charge for the content of the call or other product or service delivered in the course of, or as a direct consequence of, the call, which charge is in addition to, or forms part of the overall charge for, the telecommunications service which delivers that content, product or service.

A7.4 Premium Rate Non-Content Services in the 091 sub-range are those Premium Rate Services which are not Premium Rate Content Services.

A7.5 Allocation of numbering in the 090 and 091 ranges will normally be in blocks of 10,000, although tariff distinctions will be made at the 100,000 level. The length of 09 numbers shall be ten (10) digits (excluding the national prefix ‘0’).

A7.6 In order to provide service and tariff meaning to callers, codes will be allocated with B-digits having the following significance:

0900/0901	Time charged calls up to and including 60ppm and total call cost not greater than £5 or fixed fee up to £1 per call.
0902/0903	Protected for PRS expansion.
0904/0905/0906	Open ended time dependent charge or fixed fee.
0907	Pay for product that costs more than £1 in total.
0908/0909	Sexual Entertainment PRS.

A7.7 Further sub-ranges may be designated by Oftel for specific services/tariffs from time to time. Information notes published by Oftel in the Numbering Bulletin will set out any new sub-ranges.

Sexual entertainment Premium Rate Services

A7.8 In order to provide service meaning to callers, premium rate sexual entertainment services, regardless of the charge for the content, product or service, shall only be promoted and accessed using 0909 and no other service meaning shall be given to 0909. Sexual entertainment services are entertainment services of a clearly sexual nature, or any services for which the associated promotional material is of a clearly sexual nature, or indicates directly, or implies, that the service is of a sexual nature.

  A8: Broadband Services (092+)

A8.1 The ranges 092 to 099 have been designated for the use of Broadband Services. These are services that allow a considerable amount of information to be conveyed, such as television pictures. Broadband is generally defined as a bandwidth that is more than 2Mbits per second. Broadband Services will in most cases be services incapable of connection to or from numbers in other narrowband numbering ranges.

A9: Access codes and short codes

A9.1 Access codes are short, generally memorable, three to six digit numbers, usually beginning with ‘1’, which allow end users to access a wide range of telephony services. Lists of codes in use or designated for use is included in the access codes sections of the Scheme.

A9.2 Access codes are categorised by the type of service for which they are used. There are three types of access codes: Types A, B and C.

Type A access codes

A9.3 Type A access codes are used by callers to reach commonly used services, such as ‘100’ (operator services) or ‘123’ (speaking clock). These codes may be used throughout the United Kingdom by all operators offering equivalent services (and may not be used by any operator for any other service). More recently, the use of Type A codes has been refined for particular services where there is a social imperative, sometimes backed up by regulatory force, such as ‘141’ (suppress calling line identification) and ‘1800X’ (voice text services for the deaf). Type A codes will be designated individually by Oftel for such services, not allocated to a particular operator or a service provider.

Type B access codes

A9.4 Type B access codes have network-wide significance as they are used by the end users of one public telecommunications operator to have selected calls connected by an operator other than the one from whom they rent their telephone line (known as ‘Indirect Access’). For example, callers might use Type B codes to select Indirect Access providers for long distance and/or international calls. Type B codes can also be used by callers to access services available from their own operator’s system or another public operator’s system. These codes are allocated by Oftel.

Type C access codes

A9.5 Type C access codes are set aside for independent use by public telecommunications operators, either to provide particular services exclusively to their directly connected end users or for internal network operations. The access code ‘150’, which is used by British Telecommunications plc for residential sales and billing enquiries, and by Orange Personal Communications Limited for customer services, falls into this category. Operators of different systems have the opportunity to choose corresponding codes where it is convenient and potentially beneficial to adopt a common approach, but are not obliged to do so. While Oftel has designated a range, it does not allocate Type C codes but, based on information supplied by operators, their use is recorded in the Scheme.

Number of digits

A9.6 Given the need to ensure reasonable numbering capacity, allocation of access codes will generally be on the basis of five-digit ‘1XXXX’ codes. While three- and four-digit codes will no longer be issued, three- and four-digit codes already in use will remain in use. Access codes may, however, be withdrawn in accordance with Convention 6.

A9.7 Where appropriate, different access codes may be linked together such as, for example, to allow choice of operator followed by access to a second operator’s service. However, there may be limitations on the number of digits that the public system can handle in a single string (see Convention A2.4).

Entitlement to allocation and maximum permissible holdings

A9.8 Type B access codes will be allocated on the basis of Company Groups, with the entitlement generally being restricted to one access code of each type set out in Convention A9.9 for each Company Group. Oftel will consider requests for additional access codes on a case by case basis. However, those who already have shorter-length access codes shall not generally be allocated new codes, and will be expected to extend their existing access codes.

A9.9 There are generally three types of Type B Access Code:

Emergency numbers

A9.10 In order to minimise the risk of misdialling or incorrect routing on emergency calls, the use of digits ‘999’ and ‘112’ in prominent positions in longer number strings should be avoided.

Short codes

A9.11 As outlined in Convention A2.7, digits other than ‘0’ and ‘1’ may be designated by Oftel for public use (such as in the case of ‘999’), but may not be used for other purposes. However, Oftel is aware that certain operators use the ‘2XX’ to ‘9XX’ dialling space as a means of providing end users with access to certain services and facilities, on networks where only full national dialling is possible.

A9.12 Oftel has no current plans to formally authorise this use of such short codes. Accordingly, operators who continue to utilise such codes should be aware that there may be implications in the event of changes being made to the structure of the Scheme.

A9.13 The use of short codes represent substantial numbering capacity and, for this reason, are recorded in the details of the Scheme, where information is provided.

Conventions for other codes and numbers

1: Inbound and internal routing codes

B1.1 Blocks of numbers in the 0899 range, from 08993 0 to 08999 9, will be available for allocation to operators for inbound routing purposes. Numbers in those ranges will be ten (10) digits in length and will normally be allocated in blocks of 100,000. Operators will use the digits following 0899XX to identify service, carrier and end user. Operators will be expected to use a structure that will utilise the numbers efficiently. The need for further routing codes, or an increase in the provisional limit on inbound routing codes, will be addressed as and when necessary.

B1.2 Operators may use codes in the ranges 08990 to 08992 for internal routing purposes without application to Oftel.

  B2: Data network numbers and codes

Standards

B2.1 So far as it is practicable, the Scheme for Data Networks will conform to relevant and applicable international standards. Particular attention is drawn to the following ITU-T Recommendations:

X.121 International numbering plan for public data networks.

X.122 Numbering plan for inter-working between a packet switched public data network (‘PSPDN’) and an integrated services digital network (‘ISDN’) or PSTN in the short term.

B2.2 The country codes 234, 235, 236 and 237 have been assigned by the ITU-T to the United Kingdom for data networks. These expand by the addition of a network digit to a maximum of forty (40) Data Network Identification Codes (‘DNIC’). The four-digit DNIC is followed by up to ten digits of the network termination number to form the network user address and the normal practice is to use the full international number on all data network calls.

B2.3 The United Kingdom Scheme will use the ten-digit decimal character set 0-9 for all number allocations. Letters and other non-decimal characters will not be allocated in any circumstances.

Numbering and codes

B2.4 Data network numbering capacity will be allocated in response to requests from operators licensed to run systems offering packet-switched data services in the United Kingdom. Allocations will not normally be made unless or until the licensee has made arrangements to operate a public network in the United Kingdom, having interconnection with other such networks using the X.75 protocol or recognised alternative interconnection standard.

B2.5 The maximum allocation would be a four-digit DNIC but, in view of the possible shortage of DNIC, individual allocations will be for only one-tenth of the gross capacity of a DNIC. Further allocations within the same DNIC will be made as and when justified, but at some stage it may become necessary for underused DNIC to be shared between two or more operators. In preparation for such sharing, operators of packet-switched data systems will be expected to engineer their system to effect X75 routing on five digits rather than the four digits of the DNIC. As an interim measure, an operator requiring only a small amount of data network numbering capacity will be encouraged to share a DNIC with other operators having similar requirements. Oftel will give operators not less than six months’ notice should it become necessary for a DNIC previously allocated to one operator to be shared with one or more other operators.

B2.6 The United Kingdom is not divided geographically for the purposes of the data network numbering, although an operator may use the first few digits of the network termination number to route calls through to particular destinations serving end users within the DNIC range allocated to that operators network. A list showing the state of each of the United Kingdom’s DNIC is given in the data networks section of the Scheme. The licensed operator receiving an allocation of data network numbering capacity will be responsible for allocating individual numbers to end users.

B2.7 In accordance with ITU-T Recommendations, certain digit values will not be used as the initial digit of the country code and/or DNIC, but may be used for other purposes listed below:

1 DNIC in this range are used for public mobile satellite systems.

8 Escape from data network to telex (F.69).

9 Escape from data network to PSTN/ISDN (E.164 Analogue).

0 Escape from data network to PSTN/ISDN (E.164 Digital).

B2.8 Oftel does not expect to allocate data network numbering capacity to private network operators, nor to operators of public networks where there is no intention to interconnect with other public networks. However, such operators may apply for a reservation of capacity in the form of a ‘latent’ DNIC, as described in the Oftel publication entitled ‘Future allocation of Data Network Identification Codes (DNIC)’, issued in 1989.

B3: Telex numbering

Information on number allocation for telex services is available from Oftel.

Glossary

Annual Numbering Return - Information supplied by operators to Oftel, at Oftel’s request, in a manner prescribed, and usually within one month of the year’s end.

Broadband - A service or connection allowing a considerable amount of information to be conveyed, such as television pictures. Broadband is generally defined as a bandwidth that is more than 2Mbits per second.

Company group(s) - ‘Company group’ has the same meaning as the term ‘group’ as outlined in Section 262(1) of the Companies Act 1985; namely it means a parent undertaking and its subsidiary undertakings (both of which are defined in Section 258 of the Companies Act 1985).

Conservation area - A geographic code area that has a realistic expectation of number exhaustion within the foreseeable future. This definition is based on knowledge of operators’ business plans in a particular area or, generally, the amount of numbering capacity available and on information provided in operators ‘Annual Numbering Returns’. Oftel will publish and keep updated the list of Conservation Areas and it will be available on the Oftel website.

The Conventions - The United Kingdom’s National Numbering Conventions. These are a set of rules and principles that govern the use, management and allocation of numbers from the Scheme. It is a breach of the Numbering Arrangements Condition, contained in the licence granted to an operator under Section 7 of the Telecommunications Act 1984, for an operator to not have a Numbering Plan, or to have a Numbering Plan that does not accord with these Conventions.

Country code (CC)* - The combination of one, two or three digits that identifies a specific country or countries in an integrated numbering plan or a specific geographic area. The public switched telephone network CC for the United Kingdom is 44. This code follows the international dialling prefix on calls made from outside the United Kingdom, and should be followed by the NSN of the destination within the United Kingdom, excluding the national dialling prefix, ‘0’.

Data Network Numbering and Data Network Identification Code (DNIC) - Data network numbering conforms to international standards and is assigned to the United Kingdom by the ITU-T as required. A four (4) digit DNIC is followed by up to ten (10) digits of the Network Termination Number to form the Network User Address, and the normal practice is to use the full international number on all data network calls.

The Director - The Director General of Telecommunications.

‘Find-me-anywhere’ services - These are services that enable end users to be contacted, whatever their location, where the call charge is not distance dependent. Mobile, personal numbering and paging services shall all use the ‘07’ range.

ITU Telecommunications Standardisation Sector (ITU-T) - The ITU-T is a permanent organ of the International Telecommunication Union (‘ITU’), the United Nation’s specialised agency in the field of telecommunications. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardising telecommunications on a world-wide basis.

Local rate - An indication that the price for the call is equivalent to the rate for a geographic local call set by the relevant originating operator, where such a rate exists.

Mobile service - A telecommunications service consisting in the conveyance of messages by means of a telecommunication system, where every message that is conveyed thereby has been, or is to be, conveyed through the agency of wireless telegraphy to or from a telecommunication system which is designed or adapted to be capable of being used while in motion.

National Destination Code (NDC)* - A nationally optional code field, within the international public telecommunications numbering plan as set out in the ITU-T Recommendation E.164 number plan, which, combined with the subscriber number, will constitute the National Significant Number. In the United Kingdom, this corresponds to the area code, used before the called subscribers number, where the calling and called subscribers are in different numbering areas. In the United Kingdom, the NDC varies from two (2) to five (5) digits.

National Rate - An indication that the price for the call is equivalent to the rate for a geographic national call set by the relevant originating operator, where such a rate exists.

National Significant Number (NSN)* - This refers to that portion of the number that follows the country code for geographic areas. The National Significant Number consists of the National Destination Code followed by the Subscriber Number. In the United Kingdom, the standard national destination code is ten (10) digits.

Number Block - A unit of 1,000, 10,000, or 100,000 numbers depending on the section of the Scheme to which the number pertains.

Number Portability - This is a facility whereby subscribers who so request can retain their number on a fixed public telephone system and on the integrated services digital network (‘ISDN’), independent of the organisation providing the service at the network termination point of a subscriber at a specific location, in the case of geographic portability, or at any location, in the case of non-geographic portability.

Number Range - A set of contiguous numbers of a specified or unspecified size.

Numbering Arrangements Condition - The condition contained in certain licences granted under Section 7 of the Telecommunications Act 1984. This deals with numbering arrangements in respect of numbers commonly referred to as ‘public numbers’, such as a licensee’s obligation to adopt a numbering plan for such numbers allocated to him by the Director General of Telecommunications from the Specified Numbering Scheme in accordance with the Conventions. This is currently Condition 26 of PTO licences, and Condition 22 of the Telecommunications Services Class Licence (‘TSL’) and equivalents in other licences.

Numbering Plans - Plans that licensed operators adopt for such numbers as are allocated to them from the Scheme. These plans describe the method adopted, or to be adopted, for allocating and reallocating a number to any network termination point, user, telecommunication apparatus or service element. The Numbering Arrangements Condition in the licence granted under Section 7 of the Telecommunications Act 1984 obliges a licensee to have a numbering plan that is consistent with the Conventions. Pursuant to that condition, the Director may request such information about the licensee’s operations under its numbering plan as he may reasonably require to administer the Scheme.

Operator - A person, usually a corporation, that runs a telecommunications system under a licence granted in accordance with the Telecommunications Act 1984.