Ported Number Not Receiving Calls From Certain UK Networks? Here’s Why

You’ve switched mobile providers, kept your number and everything seems fine.

Your new SIM has signal.

Mobile data works.

You can make calls.

Your partner can call you.

Then someone on another UK network tries to call.

Nothing.

No ringing.

No missed call.

Sometimes they hear an automated message saying your number is unavailable or cannot be reached.

This is one of those problems that makes you wonder whether your phone has randomly decided to dislike certain people.

It probably hasn’t.

If your ported number not receiving calls from only certain UK networks, the problem can point towards inter-network routing rather than a problem with the SIM itself.

The Number That Worked for Some People but Not Others

James moved his number from one UK provider to another.

He tested it with his wife.

Her call came through.

Then his colleague called from a different network.

Nothing.

His brother tried another network.

Still nothing.

James could make outgoing calls without a problem.

That was the clue.

His new SIM was connected correctly, but calls coming from certain networks were not consistently finding the new destination for his number.

This is sometimes described as a routing or porting issue.

Why Can One Network Call You While Another Cannot?

When somebody calls your mobile, their network needs to know where your number currently lives.

After a port, that information needs to reflect your new provider.

The simplified journey looks like this:

Caller

↓

Caller’s Network

↓

Number Routing

↓

Your New Network

↓

Your Phone

If the caller’s network has outdated routing information, the call can be sent down the wrong path.

That is why the problem can appear selective.

What happens	What it suggests
Everyone can call you	Port is probably fine
Nobody can call you	Wider routing or activation problem
Some networks can call	Possible inter-network routing issue
Only one number fails	Could be caller-specific
Outgoing calls work	Your SIM is probably active
Old SIM still rings	Old routing may still exist

The last two together are particularly useful clues.

A Port Does Not Just Change Your SIM

Your mobile number is not physically stored inside the SIM card.

The SIM identifies your service.

The wider network infrastructure decides where calls and messages should go.

When you port, those systems need to recognise that your number has moved.

Ofcom says a normal UK mobile switch using a PAC should usually be completed within one working day after the new provider receives the request.

That does not mean every individual routing record everywhere updates at exactly the same second.

Most customers will never notice this.

Occasionally, though, one route doesn’t get the memo.

Why Does It Sometimes Affect One Network?

Imagine someone on Network A calls you.

The call reaches your new SIM.

Someone on Network B calls.

It fails.

That can suggest Network A has the correct routing information while Network B is still using an outdated or incorrect route.

This is particularly useful information for support teams.

Instead of saying:

“My number doesn’t work.”

tell them:

“Calls from Network A work, but calls from Network B cannot reach me.”

That is much more specific.

Test Before Changing Everything

Before resetting your phone, try a simple test.

Ask people on different networks to call you.

Ideally test:

• One EE number
• One O2 number
• One Vodafone number
• One Three number
• A landline if available

You don’t need a scientific laboratory.

Two or three different networks are enough to identify a pattern.

Also test outgoing calls.

If outgoing calls work and incoming calls fail only from certain networks, your phone settings are unlikely to be the main problem.

What Should You Do?

1. Restart Your Phone

It sounds boring.

Do it anyway.

Talk Home Mobile specifically recommends restarting the device as the first troubleshooting step for mobile number transfer issues.

2. Toggle Airplane Mode

Turn it on for around 30 seconds.

Turn it off.

Allow the phone to reconnect.

3. Test Different Networks

Write down which networks can and cannot reach you.

That information is more useful than simply reporting that calls are not working.

4. Keep the Old SIM

If you still have it, keep it available while the issue is being investigated.

If the old SIM receives calls that the new SIM doesn’t, tell your new provider.

5. Contact Your New Provider

If the issue continues after the port has completed, your new provider needs to check the routing.

Don’t spend an hour changing APN settings.

APNs control mobile data.

They do not normally determine which network routes an incoming voice call to your number.

When Should You Contact Support?

Contact your provider if:

• The port completion date has passed
• Incoming calls still fail
• Only certain networks can reach you
• Your old SIM still receives calls
• The problem lasts beyond the expected switching window

Ofcom says customers may be entitled to compensation when a mobile switch takes longer than one working day or there is an abuse of the switching process.

Your provider can also check whether the port itself completed correctly.

Where Talk Home Mobile Fits

Talk Home Mobile supports customers who want to keep their existing UK number when moving to the network.

Its current port-in process requires the existing provider’s PAC and says that requests submitted before 5pm are normally completed the next working day, while requests after 5pm can take two working days.

If a Talk Home Mobile customer can make calls but cannot receive calls from a particular UK network, the useful information to provide support is:

• Your number
• Port date
• Which networks can call you
• Which network cannot
• Whether outgoing calls work
• Whether the old SIM still receives calls

That gives the support team a much clearer picture of a possible routing issue.

Final Thoughts

A ported number not receiving calls from certain UK networks can look completely random.

It usually isn’t.

If your new SIM works and callers on some networks can reach you, the problem may sit somewhere between the caller’s network and your new provider.

Test from different networks.

Write down the pattern.

Then give those details to your provider.

You don’t need to replace the phone just because one network seems to have lost your number somewhere along the way.