How to transfer your number from Three Mobile to O2?

1) Check you’re eligible to switch from Three

In the event that you’re out of contract, you’re free to switch whenever you like for no charge.

To find out your contract end date, you can:

Open up the Three app on your phone. Then click the ‘Plan’ icon at the bottom and scroll to the foot of the page, where you’ll find the date you’re free to leave.

Don’t have Three’s mobile app? No problem. You can also check your contract end date by logging into your Three account on Three’s site.

Prefer to call? You can get in touch with Three's customer support team on 333 from your Three phone. Or on 0333 338 1001 from any other phone (standard network charges apply).

And if you’re interested in switching but want a bit more information first, text INFO to 85075.

2) Contact Three to cancel your contract and get your PAC code

Okay. Now we’re really moving. With your new phone or SIM card winging its way to you, the next thing you need to do is contact Three and tell them you’d like to leave. At this point, you’ll be given a contract end date.

You can contact Three's customer support team by calling 333 from a Three phone. Or on 0333 338 1001 from any other phone.

Or, thanks to Text to Switch, you can just text PAC to 65075. You don't even need to make a phone call.

While you’re on the phone to Three, you also need to ask for a PAC Code. This is a short, alphanumeric code that you’ll need to transfer your phone number to the network you’re joining.

Three is bound by law to provide you with your code within two hours of your request. Once you’ve got the code, it’s a very good idea to make a note of it.

Your PAC code expires after 30 days. So if you haven’t used it within this timeframe, you’ll have to contact Three to get another one.

3) Early upgrades

Three does not offer a mid-contract early upgrade scheme that’s comparable to O2 Refresh or Tesco Mobile’s Anytime Upgrade.

However, customers on Three’s phone and contract plans are offered an upgrade with 30 days remaining on their contract.

4) Find and buy a new deal from O2

Your next task is to choose and sign up for a new deal contract from O2. Once you’ve passed O2's credit checks, you’ll receive your phone or SIM card in the post.

5) Contact O2 to give them your PAC code

Now you’ll just to ring O2 to give them your PAC. You can get in touch with O2's customer support team on 034 4809 0202 from a landline (standard network rates apply).

6) Insert your new SIM card from O2

If you got a new phone, use your pin-key to unlock the handset's SIM tray. Then insert your O2 SIM.

If you went for a SIM-only deal, you can just put the O2 SIM in your existing phone.

While your number is being transferred, you'll be supplied with a temporary number to use. So you can still make and take calls and do whatever you'd normally do on your phone.

7) Wait for your number to be transferred from O2

The transfer should be complete the next working day. But this varies depending on the network you're joining.

The transfer could also take a little bit longer if a weekend or Bank Holiday gets in the way.