How do different mobile carriers not set up new customers with the same phone number?

Question

How does a new T-Mobile customer and Verizon customer not get the same number? Do companies share the same number generator? How can Apple systems tell a number doesn’t come from apple messager?

In: 6

Answer 1

Each carrier buys “blocks” of numbers for use.

So for example in Australia you can download this file. And see which telco has “bought” which numbers.

https://thenumberingsystem.com.au/#/number-register/search

Apple’s iMessage is another topic. And it checks an internal apple data base to see if the number is registered before sending an SMS.