topic Re: Unknown Caller ID for Contacts. in Tech Support

Unknown Caller ID for Contacts.

James_A — Tue, 11 Jul 2023 18:54:23 GMT

All my Incoming calls are Unknown, which includes Contacts stored on phone.

I have caller ID and Spam protection turned on.
I have reset Phone on numerous occasions, problem still remains.
This problem arose when I changed my Sim card to a new one. Believing the new sim to be faulty I got a new one, to encounter the same Issue.
My number has not changed since I first contracted with O2.

Any suggestions on how to resolve this matter would be appreciated.

Re: Unknown Caller ID for Contacts.

pgn — Tue, 11 Jul 2023 19:28:20 GMT

Take your phone and photo id to an O2 store, a replacement SIM has fixed this recently for another customer here. Good luck, don't let the cowboys in store sell you anything either, @James_A

Re: Unknown Caller ID for Contacts.

James_A — Tue, 11 Jul 2023 20:09:04 GMT

Thank You for responding PGN,
My previous sim encountered this problem. This is the second sim card that has encountered the same issue.
Why would 2 brand new sim cards encounter the same Unknown caller ID issue for all Incoming calls?

Re: Unknown Caller ID for Contacts.

MI5 — Tue, 11 Jul 2023 20:20:45 GMT

@James_A

Try turning off wifi and 4g calling in phone settings to see if it helps?

Re: Unknown Caller ID for Contacts.

James_A — Tue, 11 Jul 2023 20:56:10 GMT

Thank You for the suggestion MI5,
Turned off 4G calling (wi-fi calling was already off), reset phone and still same issue.

Re: Unknown Caller ID for Contacts.

MI5 — Tue, 11 Jul 2023 21:08:23 GMT

@James_A

I'll ask @O2Sarah- to check in with you in the morning.

May need CLID resetting on your account.

Re: Unknown Caller ID for Contacts.

James_A — Tue, 11 Jul 2023 21:18:28 GMT

Many Thanks MI5.

Re: Unknown Caller ID for Contacts.

O2Sarah- — Wed, 12 Jul 2023 07:13:31 GMT

Thanks for the tag @MI5

@James_A I will send you a private message so we can check your account.

Re: Unknown Caller ID for Contacts.

Woody45 — Wed, 19 Jul 2023 04:02:51 GMT

Hi having same issue on sony Experia since getting new O2 simcard after switching from virgin ,tried everything .

Re: Unknown Caller ID for Contacts.

Bartosz-88 — Sun, 17 Sep 2023 12:53:05 GMT

Hi , I got the same issue . All calls come as unknown and it’s affecting my business . Need to get this sorted asap . Please someone help me

Re: Unknown Caller ID for Contacts.

pgn — Sun, 17 Sep 2023 13:03:56 GMT

The only way to get this resolved is to engage with O2 - you can either go into an O2 Shop with some photo id and let them help you, or reach out to O2 directly by calling 202 or by using Social Media as described in the link just below this post will work, @Bartosz-88 - good luck!

Re: Unknown Caller ID for Contacts.

MarkusC — Fri, 01 Aug 2025 14:06:17 GMT

Hello, I'm having the exact same issue. All contacts which are clearly labelled are all coming through unknown. O2 support bot was as useful as a chocolate tea pot. Please help

Re: Unknown Caller ID for Contacts.

jonsie — Fri, 01 Aug 2025 14:09:45 GMT

We’re just customers like you but it sounds like you’ll need someone to access your account which can’t be done from here. If you message O2 using the links below, they should be able to help you with this

or give them a call on 202 or 0344 809 0202

Guide: How to find help & contact O2