Help Products Messaging Gateway Why are my SMS messages not delivered?

Why are my SMS messages not delivered?

Remco Magielse
Remco Magielse
Updated 5 years ago

Sorry to hear that your messages are not being delivered. This can have many reasons:

Are your request being accepted by the CM API?


Which error code is displayed? Click on the following link to see the error codes and the descriptions.

Some common examples are:

  • Quota Violation: You don't have enough credit, you need to top up your account.

  • Undeliverable: Used when the message is undeliverable due to an incorrect / invalid / blacklisted / permanently barred MSISDN for this operator. This MSISDN should not be used again for message submissions to this operator.

  • Invalid credentials: Your API Key or Secret are incorrectly specified?


Your next step is to understand any restrictions or rules in place for you destination country. Some countries will not support DLR's so a Pending status may not indicate a failed delivery. Others have strict Do Not Call lists in place. There are other destinations that will require you to pre-register your sender ID before your traffic will be accepted. The US/Canada will require you to purchase a local LVN (Long Virtual Number) to use as your sender ID.

There are many different variables that can affect your traffic in each country, please check our full country specific listings to help you understand what the issue could be. You can view this in the Country Specifics subcategory.

If none of the above apply you may find failed delivery is due to a handset related issue such as:

  • The sender ID is too long, it can have a maximum length of 14 digits or 11 characters. Only the following characters are possible: A to Z, a to z and 0 to 9. No spaces or any other symbols and characters are possible.
  • handset is permanently incompatible or unable to receive this type of message.
  • undeliverable because the subscriber is temporarily absent, e.g. his/her phone is switch off, he/she cannot be located on the network. The operator will try to deliver for a certain validity period.
  • message has failed due to a temporary phone related error, e.g. SIM card full, SME busy, memory exceeded etc. This does not mean the phone is unable to receive this type of message/content.

If you find that you still do not have a clear answer as to why your message is not delivered, please check our Status Page ( to see if there are any major known issues. If not then our dedicated support team will be happy to help resolve this issue for you. You can send an email directly to [email protected], or you can create a ticket via your own CM Direct Account. Please include as many details as possible, such as CM message ID or API key, destination number and timestamp.

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