My SMS was not delivered
Non-delivery means we were unable to deliver the message. There can be multiple reasons why an SMS does not deliver. Here are some of the most common reasons your SMS might not be delivered. Click the links to learn more or scroll through the topics.
Number Formatting
When sending your SMS via our dashboard or API, you should make sure all numbers are entered in international format. To do so, add the country prefix, and take off the + and the first 0 from the number. A few examples below:
Dutch number, country prefix(+31): 0612345678, should be entered as 31612345678
UK number, country prefix (+44): 0712345678, should be entered as 44712345678
For more information see here: Numbers format.
Number unable to receive SMS
Phone switched off
If a phone is switched off, we are unable to deliver an SMS to that number at that time. To resolve this simply switch on the phone and make sure it has a good connection to the network.
Note that each SMS has a validity period during which the SMS must be delivered, otherwise it fails. You can read more about the validity period of an SMS here: Setting a Validity Period for your SMS
Network restrictions
Under a few circumstances the network may block the number from receiving SMS:
The phone is on a Do-Not-Disturb (DND) list for SMS services. This is usually initiated by the customer through their provider.
The network has put a block on the number, for example, due to unpaid bills
Your end-user can reach out to their provider for more information.
Landlines
If you are sending an SMS to landlines, we cannot guarantee these are able to receive the message. Certain landlines are able to play a spoken version of the SMS, whereas others are unable to do so. This is out of our control.
Application-to-Application (A2A) messaging
Our platform is optimised for messaging with end-users, so we are unable to troubleshoot any A2A issues. If you are trying to send SMS to another application, we cannot guarantee this will work.
Connection Issues
Number out of network coverage
We are unable to deliver an SMS if the phone is switched on but out of network coverage. It is also possible for the phone to have an issue with the Application-to-Person (A2P) network, which we explain more about here. In this case it is also not possible for us to deliver the SMS until the phone has reconnected to the A2P network. Most connection issues are resolved by simply restarting the phone as this refreshes the connection to the network.
Note that each SMS has a validity period during which the SMS must be delivered, otherwise it fails. You can read more about the validity period of an SMS here: Setting a Validity Period for your SMS
Roaming numbers
We cannot guarantee delivery for numbers in roaming. Whether or not the SMS can be delivered depends on agreements between the home network and the roaming network. This is out of our control.
Local Restrictions
Many countries and networks have restrictions regarding SMS content and senders. Please check to make sure you are adhering to local restrictions, as not doing so can cause issues with SMS delivery. You can see more information on this page: Country Restrictions and Regulations
API Issues
Using test keys
Using a test key in your API request will test the connection, however, it will not send out any SMS. Instead, you will receive a response code to let you know if your request was successful. If you want to send SMS you must use a live key.
API errors
Successful API requests will receive a successful API response. If your SMS did not arrive, it is possible there was something wrong with your API request. If you received an error, review our API Errors to see what went wrong.
Contacting MessageBird support for non-delivery issues
If you were not able to solve the issue based on the points mentioned above, please contact our support team with the following information:
Your Workspace ID
At least 3 affected recipient numbers (the more examples we get the easier it will be to investigate the issue).
A description of the issue you’ve encountered.
Date and timestamps (including time zone) when the messages were sent.
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