There are numerous reasons why SMS texts in Android can fail to send (or be received, but this article will focus on the failure to send). If you cannot receive SMS texts, you can check out Phone Not Receiving Texts. However, if you can receive texts just fine, but your texts always fail to send, the issue most likely lies with your SMSC number. This is not a hardware or software issue; factory resetting your phone will accomplish nothing. This is because the SMSC number is actually written to your SIM card, not on your device.