It is the most frequent question about SMS, and the answer often disappoints: the SMS format has no read receipt at all. The blue double ticks that messaging apps have accustomed us to have no equivalent here, and probably never will.
Three things that get conflated
The misunderstanding comes from three different notions sharing one everyday word.
Acceptance: the gateway or the operator confirms it has taken charge of the message. That acknowledges the request, not the delivery. It is the only signal this service provides.
Delivery: the network confirms the message reached the recipient's handset. This is called a delivery report, and it genuinely exists in the standard — but it has to be requested at send time, and not every operator returns it reliably.
Reading: the recipient opened the message. That information simply does not exist in the SMS protocol. No operator, no gateway and no app can give it to you for a standard SMS.
Why the limit exists
SMS was designed in the late 1980s as a secondary service, tucked into the GSM network's signalling channels. Those channels existed to run the network itself, not to carry content. The space constraint that produced the 160-character limit also cut everything that was not essential — and knowing whether a message had been read was not.
An app like WhatsApp, by contrast, runs over the internet with software installed at both ends. That software can report whatever it likes, including a conversation being opened. SMS has nothing at the other end: just a phone, whichever one it happens to be.
What this service tells you, and what it does not
Our gateway confirms that a message was accepted for delivery. That is all. We provide no delivery report and no read receipt, and we would rather write that plainly than let anyone believe otherwise.
In practice, if your message does not seem to have arrived, there is nothing on our side to consult that would tell you. The troubleshooting page on messages not received lists the possible causes, but none of them can be confirmed remotely.
The only reliable signal is still human
A message is only certainly read when someone answers it. That is frustrating, but it is also the one signal that cannot be faked — a blue double tick means an app displayed a screen, not that a person read it.
If the reply matters, two habits help: ask for it explicitly in the text, and sign your message. Because the send leaves from our gateway's number, the recipient otherwise gets a message from an unknown number, which sharply reduces the chance of a response. The page on how to read the reply to an SMS explains where it lands.
