At US Mobile, we currently offer two networks that customers can choose from GSM LTE (the white SIM card) and Warp 5G (the black SIM card). Each has its own compatibility, coverage, and list of available features. You can find more information here.
Compatibility with GSM LTE (white SIM card):
Due to recent changes in the infrastructure powering our GSM LTE network, many older devices will no longer be compatible with GSM LTE unless they also have the VoLTE/HD Voice/Enhanced Calling feature. This applies to all NEW activations (starting from 9th June 2021).
While existing customers on older devices may not currently be affected by this, as time goes on, 2G and 3G support on the GSM LTE network will also eventually be phased out, resulting in poor/degraded service on such devices. That is why, we advise customers joining our GSM LTE network to have "4G" or "LTE" compatible devices, which possess LTE Band 4 (1900/2100 MHz) and LTE Band 12 (700 MHz), as well as VoLTE. This ensures no disruptions as the network evolves, and you can enjoy seamless service in the future.
Compatibility with Warp 5G (black SIM card):
The requirements for our Warp 5G(Previously Super LTE) network are a bit different, so we have a handy compatibility checker built into the ‘Networks’ page (Note: this compatibility checker can also be used to check which network has the best coverage in your area). Just enter the 15 digits IMEI for your device, which you can get by dialing *#06# from the device's dial pad, to know if you can use it on Warp 5G.
We advise customers joining our Warp 5G network to have VoLTE/HD Voice/Enhanced Calling to be present on the device. Moreover, the device should also possess Band 4 (1700/2100 MHz) and Band 13 (700 MHz). In case you have any questions or confusion, we highly recommend that you contact us with your phone's make and model + IMEI so we can check which network fits it best.
If your phone isn’t compatible or you need a new one, we have a selection of inexpensive and unlocked devices in our store, which are compatible with both of our networks!