If a cell phone is stolen or lost, a cell phone provider will utilize a cell phone's International Mobile Equipment Identity number to blacklist it. This prevents the cell phone from being used in the event of theft. If you purchase a used cell phone, you can contact the service provider and using the IMEI number, you can check if the phone is blacklisted. If your phone was reported as lost or stolen and you got it back, you will need to call your service provider to unlock it so that it can be usable again.
Contact your service provider through its customer service number. Make sure that you inform them that you have a blacklisted phone in your possession, or they will not reactivate it. One thing, though, the service provider will not unblock the phone if it is a stolen phone.
Prove your identity to the service provider with you Social Security number, address and cell phone account number. If the service provider cannot do this over the phone, move on to step 3.
Visit your cell phone service provider’s retail store in your area. Show the customer service representative your service contract and other personal identification, as described in step 4. The customer service representative should be able to confirm your identity and reactivate your cell phone.