Insights Ofcom consults on Calling Line Identification (CLI) authentication – a potential approach to detecting and blocking spoofed numbers

Ofcom is seeking feedback on a potential new approach to detect and block “spoofed” numbers. This is a common tactic used by scammers to trick people into thinking a phone call is from a trusted person or organisation, such as a bank.

Rules and initiatives are already in place to block scam calls and texts. However, Ofcom explains, scammers’ tactics are constantly evolving and becoming more sophisticated, meaning that there is no single solution that will stamp out scam calls.

Ofcom is now exploring how technology can help prevent these calls at source in the future through a CLI authentication process. Under CLI authentication, the phone network of the customer making the call checks the validity of the number before it is connected to the person receiving the call. The call is connected if the number can be verified. This can prevent scammers using spoofed numbers.

CLI authentication could be achievable once the UK’s transition to digital landlines is complete. Ahead of that milestone, Ofcom has looked at how CLI authentication might work in the future. While Ofcom is not making any proposals for specific regulatory interventions at this stage, if its provisional view following this consultation is that there is a case for requiring the implementation of CLI authentication, it will publish a full assessment of the likely impact and consult on our proposals for the rules that would be needed.

Ofcom is inviting views on its suggested approach by 23 June 2023. To access the consultation, click here.