O2 how to keep your current number

o2 mobile uk keep your number

Here is information on keeping your current number straight from O2 itself.

Moving your number to O2 is simple. Just request a PAC (Porting Authorisation Code) from your current service provider, give it to us and we’ll do the rest. Your current service provider should also let you know whether you have fulfilled any contractual agreement you may have with them.



What is a PAC number?

  • A PAC lets you move your number between mobile networks
  • It contains 3 letters and 6 numbers
  • PACs are valid for 30 days from the issue date.


A PAC tells us that you’ve been given permission to transfer the number to us. We need your PAC before we can transfer your number so you’ll save time if you contact your service provider first.



What do I need to do?

  • Buy a new O2 mobile or if you’re happy with your existing handset just buy a new SIM (but make sure the O2 SIM will work in your phone)
  • Click on the ‘Keep my number form’ below.



What should I expect?


  • We’ll send you a text message on the day of the transfer to keep you up to date with things. If we do need anything else from you, we’ll get in touch by email.
  • You’ll then lose service on your O2 SIM card and your existing mobile number. Don’t worry, this is normal, it means we’re transferring your number.
  • When you’ve lost service, make sure you have your new O2 SIM in your phone and keep switching it off and on every couple of hours until you get an O2 signal on the screen. If for whatever reason you don’t, then get in touch and we’ll sort it out for you.



What do I need to know before I complete the form?

Follow the steps below:

Save any important stuff like phone numbers, text & photo messages as these may be lost in the transfer of your number 
Make a note of any important numbers on your old SIM card or mobile, and any calendar reminders as these won’t be transferred. If you have any precious text or picture messages you’d like to keep, forward them to the temporary mobile number attached to your new SIM. You’ll find this number on the packaging.

Watch out for an error message on your screen
When the transfer starts, you’ll see an error message similar to ‘SIM card registration failed’. At this point, put your new O2 SIM into your mobile.

Remember your network service will be lost for a little while
You’ll lose network service. Keep switching your phone off and on every couple of hours. When your number transfer is complete you’ll see the O2 signal on the screen.



What information will I need to fill in the form?

The form’s simple to complete – but check you’ve got these details before you start:

  • The mobile number you want to keep
  • The temporary mobile number attached to your new O2 SIM. You’ll find this either on the confirmation letter we sent if you bought online, or on your contract or SIM pack if you bought from a store.
  • Your new SIM card number. It’s on the back of your SIM card. It’s 19 digits long and starts with 89441100 (the numbers on the first 4 rows). * If you have a new iPhone Nano SIM card; the number shown will only be 11 digits long, please add 89441100 to the beginning when adding to the form.
  • If you’ve got all this you’re now ready to fill in the form.



What happens next?

When you’ve completed the form, you’ll receive the following from us:

  • An email back from us advising we’ve received your form
  • A text message from us to say everything’s fine with your number transfer
  • If we need any more information from you, we’ll send you an email.



Important Note: Under no circumstances should your existing contract be cancelled before your mobile number transfer is complete. If this happens please contact your service provider immediately.



Webform icon Keep my number form