Q: All of my immediate friends and family are iPhone users, so we regularly communicate via iMessage, which is great as we’ve been able to cancel our carrier’s expensive text messaging add-on. However, I notice that my Messages app sometimes randomly sends text messages instead of iMessages, with a green bubble and a note that says “Sent as Text Message.” Since I now pay for each of my text messages, this is a bit of a problem and I really don’t know why it’s happening or how to prevent it. Any ideas?
A: Unlike traditional text (SMS) messages, iMessage uses your iPhone’s cellular data or Wi-Fi connection to send and receive messages. This normally bypasses the carrier’s SMS services, which is why you aren’t charged for iMessages in the same way as for SMS.
The downside to this approach, however, is that for two iPhones to communicate via iMessage, they must both have an active data connection, over either a cellular data plan or a Wi-Fi network. If either iPhone is out of data coverage, your iPhone will still try to send an iMessage, however when it realizes that the message cannot be successfully delivered via the iMessage network, by default it will “fall back” to delivering it via SMS. This will result in the green bubble and the “Sent as Text Message” note that you’re seeing.
Fortunately, there is a way to turn this fallback off if you want to avoid unnecessary text messaging charges. Simply go into your iPhone Settings app, select Messages, and then toggle the “Send as SMS” option to OFF.
This will prevent your iPhone from deciding to automatically fall back to sending SMS messages when iMessages cannot be sent. Note, however, that it does not disable text messages entirely; SMS will still be used when sending to non-iPhone users, for example, but this will be clearly indicated by the green “Send” button and title bar in the Messages app.
Further, even with this option off you can individually force an important message to go out as a text message in the event that iMessage is having problems delivering it. To do this, simply tap and hold on the pending message in your Messages window, and a pop-up menu will appear with “Send as Text Message” among the options. Tapping this will send the current message out via SMS as a one-time exception—useful in those situations where it’s worth the SMS charge to ensure the message gets to its recipient as quickly as possible.