With our Bring Your Own Phone (BYOP) program, you can easily get Ultra Mobile service on your current device. Compatible BYOP devices include: Most unlocked, GSM-network phones Unlocked AT&T, T-Mobile, Cricket Wireless, Simple Mobile, Straight Talk and MetroPCS phones Most phones with a SIM card You may need to ask your carrier to unlock your phone. If you’re still not sure if your phone will work with Ultra Mobile service, visit willmyphonework.net. Once there, enter your phone’s brand and model, U.S. for country and, under “Carrier,” choose Ultra Mobile. (This, however, does not guarantee if the device is unlocked or that the phone will work with our service).