In general, if you remove your phone’s battery and see a little removable SIM chip, your phone is a GSM phone. If not, it’s a CDMA phone. On a GSM-capable iPhone, you can easily pop out the SIM tray as shown in the video here or as described by Apple here.
To make things a little confusing, though, LTE-capable CDMA devices also have SIM cards. For Sprint compatible LTE-capable devices, your phone should already have a SIM card included. You can simply use this existing SIM on Red Pocket’s service. For any other LTE-capable CDMA devices you will need a Red Pocket SIM. You can purchase a universal Red Pocket CDMA SIM here.
For further reading on the subject, we suggest PC Magazine’s short article here.
For any further questions, please contact Red Pocket Mobile Customer Service toll-free 1-888-993-3888 or chat with us at Help.GoRedPocket.com (just type in your question first). We are here for you!
CDMA devices are identified by an Electronic Serial Number (ESN), Mobile Equipment Identifier (MEID) or International Mobile Station Equipment Identity (IMEI).
For Sprint compatible devices, you must use the ESN or MEID only.
For all other CDMA device compatibility checks, you must use the ESN or MEID for 3G devices and the IMEI for LTE capable devices. Have a non-Sprint CDMA LTE-capable device? Click here to purchase a universal Red Pocket CDMA SIM.
You can find your ESN/MEID/IMEI in one of three ways:
Dial *#06# on your phone .
Go into Settings on your phone.
For iPhone : Settings >> General >> About
For Android : Settings >> About >> Phones >> Status
Remove your phone's battery and look for your ESN/MEID/IMEI on a sticker in the battery compartment.