UK mobile caller ID from abroad: withheld from 15 July 2027

From 15 Jul 2027, a call placed from outside the UK that shows a UK mobile caller ID (a +447 number) will reach the person you call as “withheld”, unless it enters the UK over a route that verifies it. Ofcom decided this on 15 Jul 2026. The call still connects; your number just stops showing.

That matters to any team that calls UK buyers from Manila, Bengaluru, Cape Town or Austin with a UK mobile number on the screen. Here is what changes, what stays the same, and what to fix before the date.

What Ofcom decided

Ofcom’s statement of 15 Jul 2026 amends its Calling Line Identification (CLI) Guidance. When a call from abroad with a +447 Presentation Number (the number the recipient sees) first reaches a UK provider, including an international gateway, that provider should mark the number as withheld, unless the call arrives over a channel that verifies it by design.

Four details matter for sales teams:

1. Withheld, not blocked. Ofcom chose to hide the number rather than stop the call.
2. The start date is 15 Jul 2027. Ofcom encourages providers to implement it as soon as possible, so some carriers may start earlier.
3. No home-routing fix. Ofcom had consulted in July 2025 on a second step that would have restored the number for genuine UK customers roaming abroad. It dropped that step as disproportionate.
4. Virtual numbers are in scope. Ofcom notes that some VoIP services offer “virtual” +447 numbers with no phone behind them, and that calls from them may start outside the UK, for example in a data center. It says those calls will still be routed and terminated in the UK, as number withheld.

Why Ofcom made the change

UK landlines closed first. Under the CLI Guidance update of 29 Jul 2024, in force since 29 Jan 2025, UK providers block calls from abroad that use a UK number as the Presentation Number, apart from a limited number of legitimate cases. UK mobile numbers were exempt so that people roaming abroad could still show their number to family and friends.

Scammers moved into that gap. Ofcom’s statement says BT stopped up to 1 million calls a day at its international gateway in the first month of blocking spoofed landline numbers. Ofcom now estimates that criminals make tens or even hundreds of millions of calls a year with spoofed UK mobile numbers.

What prospects will see, and how likely they are to answer

Ofcom’s February 2026 consumer research, quoted in the statement, asked UK phone users how likely they were to pick up different kinds of unknown calls:

What the screen shows	Likely or very likely to pick up	Unlikely or very unlikely
An unknown UK mobile number	24%	53%
Withheld	17%	62%
An unknown international number	8%	76%

These are stated intentions, not measured answer rates. Still, they point one way: a team whose +447 caller ID turns into “withheld” moves from the first row to the second.

An example, using round numbers. A team of 6 SDRs in Kuala Lumpur makes 1,200 calls a week to UK prospects with virtual +447 numbers, and 6% of calls reach a person: 72 conversations. If the share of people willing to pick up fell in the same proportion as the survey (24% to 17%), the same dials would produce about 51 conversations. That is about 21 fewer a week, before anything else changes. Your own numbers will differ; the direction will not.

Which caller ID still works when you call the UK from abroad

Caller ID on the call	Calling from outside the UK, from 15 Jul 2027
UK mobile (+447), call starts abroad	Connects, shown as withheld unless the route verifies it
Other UK numbers, such as 01 and 02 landlines, call starts abroad	Blocked since 29 Jan 2025, apart from a limited number of legitimate cases
UK number on a call that starts on a UK network	Shown as normal
A number from your own country	Shown as an international number
Withheld	Shown as withheld

Ofcom’s statement also says VoIP services can use any number type available to them, including fixed numbers, and that authorised routes into the UK exist that permit the display of UK caller ID. So the question to settle with your phone provider is where your calls enter the UK network, not only which number you rent.

A checklist for teams calling the UK from abroad

Work through this before 15 Jul 2027, and repeat the test calls in the months before, since some providers may move early:

1. List every caller ID your team shows on UK calls, by type: +447 mobile, UK landline, or foreign.
2. Ask your provider how each call reaches the UK: does it start on a UK network, or enter through an international gateway? Get the answer in writing.
3. Ask whether your +447 numbers are virtual numbers used from abroad. If yes, plan for them to show as withheld.
4. Place test calls to a UK colleague’s mobile and landline each month from the reps’ real set-up. Record what the screen shows.
5. Track connects by caller ID type. A drop that starts on one day, on +447 numbers only, points to this change rather than to your list.
6. Check the rest of the UK rules that apply on every call, such as the TPS and CTPS registers and Ofcom’s abandoned-call rules. Our guide to TPS and CTPS rules covers the registers.

Rules on number types also differ by country. Our article on international local phone numbers for business covers the UK, Germany, Australia and India.

How DialSavvy handles this

DialSavvy is the carrier for the numbers it gives you: we buy and set up local numbers for your workspace and file the registrations, as described on the telephony page. With local presence, every call shows a local number your workspace owns. The country coverage page lists the planned calling mode and the checks for the UK, with an as-of date. TPS and CTPS checks are coming.

If your team calls the UK from abroad, book a demo and bring a sample of your UK list: we will show you which caller ID your calls would carry and the checks that run before each one.