When you sell a used cell phone, what does it mean when ppl ask if it has a clear ESN?

CDMA providers such as Verizon, Sprint and Alltel don't use SIM cards - they rely on the phone itself to hold certain info.





When a CDMA phone is reported lost/stolen or payments cant be made on the account, the wireless provider can say that the ESN (number different from all phones) is blocked. When the ESN is blocked, the phone WILL function, but cannot be reactivated on the same/another account.