Sent, Delivered, Failed, Undelivered - What's the difference?

Uku Tomikas

19 Sep 2017 -

5 min read

Uku Tomikas

19 Sep 2017


2 min read

As with any service, product, tool, or feature used, certain terminology comes along with it. This can get quite confusing when the terms used seem familiar, but are used to describe events that aren’t.

Such is the case with SMS delivery statuses, and mainly the four mentioned in the heading. Here is a quick run-down of what they mean and why they’re important:


Once the nearest upstream mobile carrier has accepted the message for delivery to the SMS network where you intend to send the message, the status is updated to “sent” (from “sending” or “accepted.”) 

This does not mean that the SMS has reached the customer, but rather that it has reached the server of the carrier that delivers the SMS to the phone. So, in our case this means that the operator has received the message, but it has not yet forwarded it to the handset.


Messente has received confirmation that the message has been delivered to the recipient’s phone, where available. 

The status is updated to “delivered.” This means that the carrier has sent the message to the phone, which has returned the signal stating that the SMS is received, which gets forwarded to us. Detailed delivery reports are not available everywhere in the world, which means “sent” and “delivered” indicate the same thing, as handset delivery cannot be confirmed.


The carrier did not accept the message and delivery is not possible. 

The reasons for this may vary from missing segments (i.e., one part of a multipart SMS is missing) to operator peak time delivery issues. This does not, however, immediately indicate that there is anything wrong with the destination number itself.  


Messente has received a signal from the carrier indicating that the message was not delivered. 

The reasons tend to be related to the handset, destination number, or inappropriate message content (such as adult themes, gambling, etc.) The handset could be in roaming, switched off, or a landline number.  

Wrapping it up

Only one of these four terms indicate that the phone received the SMS. The two statuses relating to the message not being delivered can help figure out why messages aren’t being delivered, and solve the issue before contacting support.

However, if you ever need help, be sure to email or talk to us in our live chat on

What's SMS service quality?

Uku Tomikas

Lead Sales Researcher

At Messente Uku is a part of Messente’s sales lab, taking a systematic and metrics driven approach to constantly improving the B2B lead generating process. As a yoga and meditation enthusiast he likes to keep a solid balance between crunching numbers and petting his pet pup Lucy. 

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