How do phone companies let you keep the same phone number when you switch over to them?

Question

How do phone companies let you keep the same phone number when you switch over to them?

In: 1

Answer 1

Because there are laws about portability of number to prevent phone companies from being able to hold you/your number hostage basically. There are various phone-related protocols that all carriers use that allow communications between carriers, as well as ones for the transfer of numbers from one carrier to another.