The iPhone 4S I am selling is clean, and I know it is unlocked. However, when I enter the IMEI number on the Verizon "bring your own phone" online device check:
it says the phone is not compatible. I called Verizon support and they said to try the MEID for the phone, and that worked fine and said the phone was compatible. She said its best to try the MEID number for a 3G phone such as the iPhone 4S. Is this always true, and why wouldn't the IMEI work for this phone?
MEIDs are the serial number of the CDMA radio (like what Verizon uses for 3G) in wireless devices.
IMEIs are the serial numbers of the GSM radios (ones that use SIM cards like Verizon uses for 4G) in wireless devices.
Your iPhone’s MEID is compatible with Verizon’s network, but the IMEI is not.