The text service allows texts to and from the phone with the SIM. Texts can be sent to the phone by using our normal text gateway with a destination of the SIM ICCID and credentials for the text service (e.g. a VoIP account). The control pages allow texts from the phone to be sent to an HTTP address of your choice.
Not all A&A VoIP numbers can handle incoming texts. There is unlikely to ever be any discounting of inbound text charges even when we have 07 mobile numbers working for texts as we are unlikely to see incoming revenue from such texts.