Notice: On December 1, 2021, Twilio is ending support for voice calling and SMS messaging to or from Twilio Programmable Wireless SIMs. For full details, see our Voice and SMS End of Life article.
Twilio Programmable Wireless allows you to develop customized communications applications for voice and messaging using TwiML. To get started you'll need to:
- create a rate plan
- set the APN on your device
- set your SIM up to place and receive voice calls
- configure SMS to send and receive
- set up voicemail
There are a few of caveats to be aware of:
- MMS is not currently supported
- SMS to non-Twilio short codes is not currently supported
- Concatenated SMS is not currently supported
- calls to emergency services (e.g. 911) are not currently supported
- calls to non-Twilio toll-free numbers are not currently supported
- voice calls are not supported for SIMs located outside the US
- You will likely receive random calls placed to the MSISDN (the mobile station international subscriber directory number) which is the number T-Mobile has associated with your SIM that is unrelated to any Twilio numbers you have pointing at the SIM. You will not be charged for calls to the MSISDN.