Quote Originally Posted by Lemon Juice View Post
While you ask why not use INT, I would ask why use INT - because I don't see any real advantages of INT over VARCHAR and my logic says a phone number is a string of digits and not a number. There's only one 'real' disadvantage of INT I can think of: you cannot use index when doing a search using LIKE '123%'.
The whole point of using (BIG)INT instead of VARCHAR is for size and performance benefits. You can't see any real advantages to using INT over VARCHAR? What about:

* Smaller storage requirements: BIGINT = 8 bytes, VARCHAR(12) = 13 bytes
* Faster database queries.