In order to harness your full business potential, SMS and text campaigns are the way to go. With a global reach of 190+ countries and partnership with 800+ mobile networks, it is safe to say business-critical SMS is at the heart of what we do.

The world of SMS can be confusing and for those still getting to grips with the basics, the last thing we want to see after texting a brand new customer about an update is a "failed to deliver" notification. For that reason, there has never been a better time to decode the text message status.

It begins with understanding the jargon.

Industry jargon can be overwhelming and in the worst cases, it may cause you to give up entirely. However, at Messente, we utilise universal terms similar to those used across the board of texting services. Here we cover the universal meaning of our four main terms and the simple solution for each.


SENT = Message has been submitted to the cellular network or carrier for delivery. 

"Sent" gives the impression of smooth sailing but the journey of your SMS message to your customer's device has just begun.

This is where most businesses breathe a sigh of relief and continue with their day, confident that their customer has received the notification about their taxi arriving, only to find out later that the message “failed to send” and caused untold grief to the customer. We aim to equip you with the tools to spot this and rectify it.

At this stage, your text message has not reached the customer yet but has reached the server that delivers it to the customer.

Losing internet connection during this time will cause the text message to fail to reach the intended phone user and may result in a "failed to send" notification.

Why is my message stuck on SENT?

Although we use an adaptive routing system, busy periods can cause congestion for mobile networks. Sometimes if it's super busy, a server might stop their service entirely.

If your customer's phone is turned off, the message will fail to get through to their phone. A message will expire after 72 hours but when the phone is switched on the SMS will go through.

If the text remains in the "Sent" status and doesn't say "failed" assume it will reach your customer in due time.

A customer may be on a phone call or busy when you send your SMS, so avoid sending more than one SMS. If after 72 hours, the SMS is still stuck on "sent", resend the text.  


DELIVERED = confirmation the message has reached the recipient's phone but fails to show if it has been "seen" yet. 

"Delivered" is a good sign. It means that the text is ready and waiting for them to open it.

The service provider has now received confirmation that the message has been delivered to the recipient's phone. We then receive a signal stating that the SMS message has been delivered. In rare cases - Some parts of the world do not have a sophisticated mobile network and a delivery report can fail, causing the status of a text message to remain as "sent" even though it has been delivered.

When message status reports are available there are still some cases of us getting a “delivered” status when the customer’s phone has not received the text . This can be due to a full inbox or device memory issues, so clearing the cache and restarting the device can do the trick.


FAILED = Service provider did not accept the message of the carrier and delivery is not possible. 

Don't be jarred, this is an easy fix. A messaging carrier might reject the text due to technical issues rather than human error.

In our case, these issues tend to be rare since Messente’s adaptive routing system helps to avoid operator issues by using alternative connections so there is a high chance we can handle it.

What are the reasons for a failed text message?

  • Peak operating times are usually 3-5 pm on any day of the week
  • A part of the SMS is missing
  • Technical service difficulties

Quick fixes

  • Resend the text messages
  • Rarely, connections can drop and trigger the text to fail
  • Double-check that the number is correct and the SMS is complete and not missing any digits


UNDELIVERED = Service provider received a notification saying the message is "Undelivered" 

An "undelivered" status is a result of the phone, phone number, or content in the SMS being incorrect or unsuitable. Sending a text to an invalid number is the most likely cause of the issue.

Before mass-texting more phone numbers than you can count, it's worth assessing the quality of phone numbers in the database you are using. Although they might have 11 characters and all be numbers, half of them could be mistyped, landlines, or even fakes. We may be living in the future but texting a landline is space-age. Jokes aside, it's vital that your database has the correct format.

Attention to detail is key

Check that each phone number is uniform with one another.

Country codes are an example of where many go wrong. The system can end up delivering text messages to unintended numbers by using the first numbers of the non-country coded number as the country code. This is one of the most common issues a business can face and the sign that you are texting ghost numbers isn't always so clear.

Perks of being a Messente customer:

For our clients, the best way to make sure the SMS numbers are valid and able to receive the message is to use the Number Lookup API to check the numbers before any campaign.

Be vigilant

Text messages from across the world will be received differently i.e. India might be more strict on content regulation than the U.S. We advise assessing the content with your support team to prevent "Undelivered" issues.

Checklist before the SMS campaign

  1. Check the numbers are valid and not a landline number
  2. If campaigning across the globe, consider how each country will receive the text and if any laws prohibit the content you are sharing
  3. Are you about to bulk-text during a busy period? Try an avoid the times between 3 - 5 pm on any given day
  4. Is the customer you are messaging in a country where foreign numbers are blocked?
  5. If there is an issue with the delivery of an SMS, will you have a plan b or fall back-method to attempt it again?
  6. Are customer's devices capable of receiving the content you are messaging them? i.e. is the content too large in size to send via text?

SMS API Integration Checklist

In conclusion

This article aims to arm you with the knowledge needed to tackle the jargon of the SMS world.

The main takeaway - Your message is not actually being seen by your customer unless a "Delivered” status supports the text messages.

Don't let the jargon get the best of you, and you should have peace of mind that most problems are easy to fix.

Unless you have a dedicated troubleshooting team, the "failed" and "Undelivered" notifications will provide some insight as to what is going wrong.