Porting your mobile number from O2 to giffgaff

Leaving O2

How to switch from O2 & transfer your mobile number to giffgaff

Ask for your Port Authorisation Code (PAC) from O2 customer services by contacting them, either from your 02 mobile phone on 4445 for Pay As You Go, or 202 for Pay Monthly contracts. Alternatively from a landline: dial 0344 8090222 for Pay As You Go customer Service or 0344 8090202 for Pay Monthly customer Service.

If you wish to use the 'text-to-switch' service, simply SMS text PAC to 65075 free from your O2 SIM to get your PAC code by text and begin the porting process.

  • O2 will provide your Porting Authorisation Code (PAC) either over the phone, by SMS text message or via email.
  • A PAC code is valid for 30 days. If you don't use it within thirty days it will expire and you will need to request a new one.
  • Your O2 account will remain active until your number has been ported over to the new network. After the transfer is complete, your O2 account will be automatically closed.

Many of the exclusive mobile phone deals are only available online, directly from the network providers listed here. While you wait for your Port Authorization Code from O2, get the best giffgaff offer tailored to you.

Finally, provide your PAC code to your new giffgaff mobile network operator who will then be able to port your existing phone number from O2. They will tell you what day the transfer is due to take place (usually within 48 hours).

Important: Do NOT cancel your contract before switching, otherwise you may lose your existing phone number and be unable to port it over. Once you provide your new network provider with your PAC code, your old account will be clsoed automatically once the number is successfully ported over.

Note: Credit on Pre-Pay / PAYG (Pay-As-You-Go) accounts cannot be transferred over and so any remaining credit balance will be lost after the switch is complete. If you have any credit left, one good option is to donate it to a charity before porting your number.

Joining giffgaff

How to switch to giffgaff & keep your O2 mobile number

The first step is to sign up with giffgaff to get your new SIM card.

Once you have done that, ensure you have the following information ready:

  • Your original mobile phone number you want to keep.
  • The Porting Authorisation Code (PAC) from your previous O2 network.
  • The expiry date of the PAC number (valid for 30 days from the date of issue).
  • The temporary mobile number from your new giffgaff sim card.
  • You may also need the new SIM card number found on the back.

Make sure your giffgaff account and SIM have been activated. Then log in to your account and complete the transfer form to keep your old number. A Giff gaff customer support agent will then get back to you with your transfer date. Replies can be found in your giffgaff account message box.

Note: You may lose network service for a short period on the day of transfer. If this happens, turn your phone off and on occasionally, until you see the giffgaff signal on your mobile phone screen. This will indicate that the transfer is complete, and you can now use your existing phone number in your new mobile network provider.

Visit giffgaff online for more information and their latest offers on mobile phone deals.

About giffgaff

giffgaff is a mobile telephone network running as a Mobile Virtual Network Operator (MVNO) using the United Kingdom O2 network. Owned by O2's owners Telefónica, giffgaff was launched on 25 November 2009.

About O2

O2, the trading name of Telefónica Europe plc is a European broadband and mobile telephony company that originated as a collection of worldwide telecommunications companies, known in the later half of the 1990s as BT Wireless, and a global mobile data business known then as Genie Internet, both subsidiaries of British Telecommunications.