Your mobile phone number is unique. So bring it with you when changing network service providers.
Ofcom (the telecommunications regulator) has provided a mobile signal checker. The service allows you to check your location for the availability of voice, 3G and 4G services from the four main UK network operators (EE, O2, Three, Vodafone).
Since all the other mobile phone operators in the UK are provisioned ...
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.
