How to check if your iPhone IMEI is clean and unlocked?

Unlocked: Use SIM from two different Carriers. (Borrow from a friend, it takes only 2 mins)

Clean: You need to be more specific. Check coverage --> Check Your Service and Support Coverage - Apple Support

The public does not have that information. You have no way to know if a phone is stolen.

If you think it is, don't buy it.

~Lyssa