Carrier access code

A carrier access code, or CAC for short, is like a secret code that lets you use a different phone company from the one you normally use.

Imagine you want to call your friend, but your phone doesn't have good signal or your carrier (the phone company you use) doesn't have coverage in that area. A CAC is a code you can dial before the phone number to use a different carrier's network to make the call.

It's like asking another company's phone tower to lend you some space to make the call, but just for that one time.

So, if you have a CAC, you can use it to make calls even if your carrier doesn't provide coverage in that area. It's like having a secret key that unlocks a different phone company's network for you.