Tackling scam calls and texts

Protecting people from scam calls and text messages is a priority for Ofcom.

Scam calls and texts are now widespread: our research has found that the vast majority of people in the UK have been the victim of a suspected scam attempt. Scams can cause significant financial and emotional harm, and impose costs on the wider economy.

This page sets out how Ofcom is responding to the problem of scam calls and texts.

Updating the Calling Line Identification guidance to block more calls with spoofed numbers

Through our CLI guidance, communications providers are expected to identify and block calls from abroad which are spoofing a UK CLI as Network Number, except in a limited number of use cases. In February we consulted on updating our guidance to extend blocking to international calls which display a UK number as a Presentation Number. We have now published a statement setting out our decision.  

We have decided to go ahead with our proposal to update the CLI guidance, - in particular paragraph 4.19 - to reflect that we expect providers to identify and block calls from abroad that use a UK telephone number as a Presentation Number, except in a limited number of legitimate use cases. We have however addressed a number of stakeholder concerns around the wording in paragraph 4.19 of the CLI Guidance and have made some additional changes to provide further clarity.  

Call for Input: Reducing scam calls from abroad which spoof UK mobile numbers 

We are concerned that some of the scam calls which are received by UK consumers may come from scammers who are spoofing +447 (UK mobile) numbers. We are now publishing a Call for Input seeking views on our initial thinking on whether we should change our rules or consider other measures to fix this issue. 

This CFI closes on 23 September 2024. 

Call for Input: Reducing mobile messaging scams 

Scammers use mobile messaging services to reach victims at a mass scale and trick them into sharing money or sensitive information. Mobile messaging scams lead to significant financial and emotional harm and can reduce confidence in telecoms services more broadly. Through Ofcom’s programme to tackle telecoms scams we have been closely monitoring mobile messaging scams. We are now publishing a Call for Input to seek views and evidence from stakeholders to further support our assessment of the scale of the problem and whether further action should be taken by Ofcom, industry, or others. 

This CFI closes on 7 October 2024. 

Experiences of fraud online and through calls and texts

Scammers use multiple channels to access potential victims, including calls (landlines and mobiles), texts and app messages.

As the regulator for both telecoms and online services, it's important for Ofcom (and the enforcement agencies we work with) to consider the many and varied ways in which people can be exposed to scams. We are publishing analysis of our latest consumer research, which looks at adults’ behaviour when using these services and measures that could be taken to prevent suspicious calls and messages reaching consumers. Further details about this research are on our stats calendar. 

Enforcement programme into phone and text scams

Our new enforcement programme will focus on identifying individual telecoms providers that allow scam and spoofed voice calls to enter the UK's telephony system, and taking action against them. We will monitor how well providers are making use of our good practice guide (PDF, 440.5 KB), which sets out the steps we expect them to take to prevent the misuse of phone numbers. The guide has been in place for over a year, so we will look at how well it has been followed.

Assessing Calling Line Identification authentication and next steps

We have also published our assessment of Calling Line Identification (CLI) authentication. This is a possible approach that could have allowed providers to detect and block calls from spoofed numbers more comprehensively.

Although we think that CLI authentication has the potential to be effective at preventing some harmful calls from spoofed numbers, we have decided not to proceed with CLI authentication at this time. This is because CLI authentication on its own is unlikely to sufficiently hinder scam calls that originate overseas, and it'd be complex, costly and time-consuming to implement. We think that other measures could reduce number spoofing scams effectively and more quickly.

Given the scale of harm from spoofed scam calls, the document also sets out several other initiatives that will seek to address this harm in the shorter term. These include exploring enhanced call tracing solutions, which aim to improve identification of the source of fraudulent calls, and exploring options to block calls from abroad which are spoofing a UK mobile number.

More information is available in the full document:

Calling Line Identification (CLI) authentication assessment and future roadmap (PDF, 651.5 KB)

Dilysu adnabod llinell y galwr (CLI) – asesiad a map ffordd y dyfodol (PDF, 248.0 KB)

Previous work

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

In April 2023 we opened a consultation inviting stakeholders to provide their views on our initial thinking about how Calling Line Identification (CLI) authentication might work in the UK, and the extent to which actions providers are already taking are likely to address the problem of number spoofing.

Improving the accuracy of Calling Line Identification (CLI) data

A common tactic used by scammers is to ‘spoof’ telephone numbers to make them appear to be from a trusted person or organisation, such as a bank. In November 2022 we published a statement which strengthens our rules and guidance for providers to identify and block calls with ‘spoofed’ numbers.

Good practice guide to help prevent misuse of sub-allocated and assigned numbers

In November 2022 we published a statement on a good practice guide which sets out the steps we expect providers to take to help prevent valid telephone numbers being misused, including to facilitate scams.

Do Not Originate (DNO) list

The Do Not Originate (DNO) list protects legitimate numbers that are most likely to be spoofed. It records telephone numbers used by organisations, such as banks and government agencies, to receive calls but never to make calls.

The DNO list is shared with telecoms providers, their intermediaries and interested parties like call blocking or filtering services, who can block outgoing calls from numbers on the list. It has been shown to be an effective tool in combating scam calls using spoofed numbers.

In February 2022 we published some updated information about the DNO list and a guide for submitting numbers to the list (PDF, 201.7 KB).

Scams survey research

Our role and approach

In February 2022, we published a policy statement that explained how we are responding to the prevalence and changing nature of scams.

• We aim to disrupt scams by making it harder for scammers to use communications services to reach consumers. We propose to strengthen our rules and guidance, while at the same time supporting providers to develop their own technical solutions to detect and prevent scam traffic.
• Scams are increasingly complex, often involving different companies and sectors. So, a coordinated approach is vital to ensure more scam attempts are blocked or disrupted. We will collaborate and share information more widely, including with the Government, regulators, law enforcement and consumer groups.
• Given the pace at which scammers change their tactics, we understand that it will not be possible to stop all scams reaching consumers. We are working to help consumers avoid scams by raising awareness so consumers can more easily spot and report them.

More information is available in the full document:

Tackling scam calls and texts: Ofcom's role and approach (PDF, 1.3 MB)

Taclo galwadau a negeseuon testun sgam: Rôl ac ymagwedd Ofcom (PDF, 188.6 KB)