Porting Authorisation Codes
(also known as PAC), are short alphanumeric codes, generated by your
old mobile provider to authorise your new network operator to transfer your phone number
over to them. They are free to obtain and valid for 30 days from the date of issue.
This allows you to keep your mobile phone number and
bring it with you when you change network providers.
You can transfer your number even after you purchase your
new mobile contract or phone SIM. It is not necessary to have your PAC number
before buying your new mobile deal, as it can be ported over at a later date.