PAC stands for 'Porting Authorisation Code' and lets you move your number from your old phone company to your new phone company.
Your PAC should be given to you straight away over the phone when you ask for it, or within two hours by text message.
Once you have your PAC it lasts for 30 days. Please try to give it to us before the 30 days runs out, otherwise you'll need to ask your old company for a new one.
Some mobile phone companies charge you for a PAC code (although we don't).