Ofcom's 2025 CLI Rules: How They Impact UK Businesses with International Users
From January 29, 2025, Ofcom is introducing stricter Calling Line Identification (CLI) rules to combat spoofing and fraudulent calls. These new requirements affect how UK telephone numbers are presented, particularly for calls originating from outside the UK. If your UK-registered business has users or offices abroad, understanding and complying with these rules is essential.
Why Are These Changes Happening?
Ofcom is targeting the increasing number of scam calls that originate from international locations but display UK phone numbers falsely. Under the new rules, phone providers must block any international calls that present a UK number, except in specific, legitimate cases.
For more details, see Ofcom’s official CLI guidance: Ofcom CLI Guidance
Key Changes to UK CLI Rules (2025)
- Blocking of Spoofed UK Numbers: Calls from international sources that falsely present UK CLIs will be blocked unless they meet certain criteria.
- Legitimate Exceptions: Some situations allow a UK CLI on an international call, such as:
- A UK mobile user making a call while roaming abroad.
- A call to a UK mobile user who is currently abroad.
- Verified UK business users making calls from non-UK locations.
- VoIP and Cloud Calling Compliance: Businesses using cloud-based or VoIP solutions for international users must verify their users to avoid being blocked.
How This Affects UK Companies with Users Abroad
If your business has employees, agents, or offices operating outside the UK, you must ensure that calls using UK numbers comply with Ofcom’s new rules.
1. UK Users Roaming Abroad
- Employees using UK-registered mobile SIMs can still make calls while abroad with their UK number displayed.
- Calls to these users will also show their UK number correctly.
2. International Offices or Call Centres
- If your company has an international office or call centre making outbound calls with UK numbers, you must ensure:
- Calls are routed through a UK network before reaching the recipient.
- Your telecom provider can verify the call’s UK origin to avoid being blocked.
3. Cloud PBX, VoIP, and Softphone Users Abroad
- If employees use softphones or VoIP services with UK numbers while outside the UK, your provider must verify their legitimacy.
- VoIP providers may require additional authentication, such as location tracking or secure SIP trunking.
4. Calls to Roaming UK Mobile Users
- If your company calls UK mobile users who are roaming internationally, these calls will not be affected by the new rules.
Steps for Businesses to Ensure Compliance
To avoid disruptions, UK businesses should take the following actions:
✔ Work with Your VoIP/SIP Providers: Confirm they are implementing Ofcom's CLI requirements correctly and will not block legitimate calls.
✔ Route Calls Through UK Networks: If you operate internationally, ensure outbound calls displaying UK numbers are processed through a UK-registered provider.
✔ Authenticate Users Making Calls from Abroad: If employees use cloud PBX or softphones outside the UK, make sure the service can verify that they are legitimate UK users.
✔ Review Call Centre Operations: If your business operates an offshore call centre using UK CLIs, ensure compliance with Ofcom’s verification and routing requirements.
Final Thoughts
These new Ofcom CLI rules are designed to reduce scam calls and increase trust in UK telephone numbers. However, UK businesses with international operations must take proactive steps to ensure their calls remain compliant.
If your business relies on UK numbers for international calling, now is the time to review your telecom setup and speak with your provider to ensure a smooth transition.
For more information, visit Ofcom’s website or check out the Comms Council UK’s summary.
Need help implementing these changes? Get in touch with your telecom provider or reach out to us for guidance on VoIP and CLI compliance solutions.
