New regulations for telecoms providers were revealed by Ofcom on 15 November in order to tackle increasing scam calls and scammers using the identity of a caller for fraudulent purposes. The new rules are specifically intended to enhance the accuracy of calling line identification (CLI) data.

CLI data

CLI data consists of the caller's identity along with a privacy marking, which shows whether the number can be shared with the recipient of the call. CLI data is exchanged between communications providers when connecting and routing a call and can similarly be used in regulatory and enforcement action, including to detect sources of so-called nuisance calls.

For example, the misuse of CLI data may make an overseas call appear to come from within the UK or to be from a well-known company. These calls expose impacted callers to reveal sensitive information or even make payments.

Amendments to current General Condition

Ofcom's current General Condition (GC) C6 requires communications providers to offer CLI facilities, except where they can prove that it is not technically or economically viable to do so. GC 6 is now being modified by Ofcom to require telecoms providers to classify and block calls with CLI data that is (i) invalid; (ii) does not uniquely recognise the originating caller; or (iii) does not include a number that is dialable.

In order to improve the consistency of CLI data presented to consumers and to assist telecoms providers in complying with the new statutory requirements, including upholding the privacy rights of individuals making and receiving calls, Ofcom is also adjusting its CLI guidance to make clear that:

  • The format of a CLI should be a 10 or 11 digit-number.
  • Providers should rely on data that recognises numbers that should not be used as CLI, including the use of Ofcom's numbering allocation information and its Do Not Originate (DNO) list.
  • Providers should detect and stop overseas calls deceptively using UK CLI, except in certain use cases specified in the guidance. For instance, it is possible that legitimate calls using valid CLI data may be inadvertently blocked when they should not be.
  • The use of 09 non-geographic numbers as CLI is not allowed.

The new GC C6 and the guidance will come into force on 15 May 2023 to allow organisations enough time to implement the new technical requirements.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.