Investigation into Tismi’s compliance with its obligations under the General Conditions of Entitlement (GCs)

Following our investigation, Ofcom has today issued a Confirmation Decision to Tismi BV (‘Tismi) under section 96C of the Communications Act 2003 for contravening General Conditions B1.6, B1.8 and B1.9(c) between at least 15 November 2022 and 1 January 2025 (the Relevant Period).

Tismi contravened these General Conditions by failing to: 

• ensure that the telephone numbers it has been allocated by Ofcom were used effectively and efficiently (GC B1.6);  
• take all reasonably practicable steps to ensure that its customers comply with GC B1 (including GC B1.9(c)) when using numbers (GC B1.8); and 
• not transfer (or sub-allocate) numbers from the UK Numbering Plan unless they are used effectively and efficiently (GC B1.9(c)).

We have found that Tismi neither met the expectations set out in our Good Practice Guide on how to prevent misuse of sub-allocated numbers nor did it have any other appropriate and proportionate measures in place to prevent misuse. As a result, we have found that Tismi failed to take appropriate and proportionate steps to ensure numbers Ofcom had allocated to it were not misused, including to facilitate scams. In particular, Tismi:  

• Sub-allocated numbers to its customers without carrying out appropriate due diligence checks to ensure the effective and efficient use of those numbers and prevent them from being misused. 
• Failed to implement appropriate measures to ensure the ongoing compliance of its sub-allocatees with General Condition B1. Specifically, Tismi did not have a process to reassess the risk of number misuse after numbers have been sub-allocated (including monitoring for potential misuse) nor an effective documented process to identify and address non-compliant behaviour. 
• Failed to ensure it had appropriate formal and documented processes in place to ensure the adequate handling of and/or consistent recording of reports of misuse. While we acknowledge Tismi provided evidence of promptly responding to queries and/or complaints from external agencies, the lack of any written or formal process meant Tismi was limited in its ability to adequately monitor and respond to the risk of misuse posed by specific customers or number sub-allocations. 

We consider this case to be a serious contravention of our rules, exposing approximately 366,000 sub-allocated numbers to potential misuse and therefore a significant number of consumers to potential harm for over two years.

Evidence of potential harm, including nuisance and scam calls using numbers sub-allocated by Tismi, was identified throughout the investigation.  Additional evidence also led to Ofcom issuing a direction to Tismi to block numbers on 20 June 2025.

Ofcom has imposed a penalty of £437,500 which includes a 30% discount on the penalty figure of £625,000 which we would have otherwise imposed, which reflects the resource savings achieved by Ofcom as a result of Tismi’s admission of liability and its completion of Ofcom’s settlement process.  

Ofcom considers this penalty to be appropriate and proportionate in the circumstances.

The penalty would have been significantly higher had Tismi not co-operated with our investigation and proactively taken steps to remedy the contravention by implementing new processes within a few months of being notified of Ofcom’s investigation.

General Condition B1 is an important rule designed to ensure the effective and efficient use of telephone numbers and prevent misuse. Scam calls cause social and economic harm to consumers and place a burden on other businesses to prevent scams and provide resolutions to consumers.

This penalty is intended to send a clear message to Tismi (and wider industry) that it is not acceptable to effectively allow allocated telephone numbers to be misused and undermine the fundamental purpose of our regulatory rules. It is intended to deter Tismi (and wider industry) from breaching GC B1 and other regulatory obligations in the future and ensure it takes, and continues to take, appropriate steps to ensure compliance from the date rules are effective. 

To ensure compliance with the General Conditions, we also require Tismi to complete further actions to evidence its compliance including providing evidence of; its due diligence process; on-going monitoring; and its response to reports of incidents of misuse in accordance with its new policies and processes.

Our Enforcement Programme into Phone and Text Scams aims to ensure that Communications Providers are complying with the rules and ensure they take appropriate and proportionate steps to disrupt nuisance or scam calls, making it harder for nefarious actors to reach consumers. It is important that Communications Providers have appropriate processes in place - including in relation to up-front due diligence checks, ongoing monitoring and reassessing risks, and responding to incidents - to prevent the misuse of numbers they have sub-allocated or assigned to business customers, and the subsequent social and economic harm that may arise.

To protect the integrity of other on-going investigations, a non-confidential version of the Confirmation Decision will not be published until a later date.