Sender IDs and Originators

Ensure that you're using valid Sender IDs and Originators for your SMS sends.

Gareth Burroughes avatar
Written by Gareth Burroughes
Updated over a week ago

This article covers general restrictions. Certain countries may have specific restrictions which are not mentioned.

Numeric Originator

When sending a message using a numeric Originator (such as a mobile number), please ensure that a plus (+) is prefixed to the number prior to sending. This will ensure that the message arrives correctly to the handset and that the recipient is able to reply.


For Alphanumeric Originators, any character within the standard GSM character set is allowed. While we do allow these characters, please note that for certain characters, some Network Providers and/or SMSCs do not always display these characters correctly. We recommend only using standard A-Z characters (upper- and lower-case) and numbers. The ampersand (&), hash (#), and exclamation sign (!) are permitted as well. In addition, please ensure that the length of the Originator is no longer than 11 characters.

Replies are not possible to messages with Alpha-numeric Sender IDs.

US and Canada

Alphanumeric Originators are not possible in the US or Canada. To learn more, check out the article Sending SMS in the US.


When sending a message containing a shortcode as an Originator, ensure that no plus signs are added and that the length of the shortcode is only five characters.


If a dedicated long number has recently been assigned to the account, ensure that half an hour has passed before any message send is attempted. The internal memory of the DMSP takes half an hour to refresh all numbers that belong to messaging accounts and, as such, won't have any records of a new number being assigned to an account until this time period has elapsed. Once the internal memory has been refreshed, the account will be able to fully utilise the number.

Originator values accepted by SMPP providers are either:

  • Numeric 5 - 15 characters (with + to indicate international format MSISDN making 16 chars max)

  • Alpha Numeric 3 - 11 characters

  • Recommended alphanumeric characters are a - z, A - Z, 0 - 9, " " (space), ".", "_", "-", "!", "&", "#".

    • Characters not allowed in the UK: "_", ",", "!", "#".

  • For additional characters, please see our article on the GSM character set. Only characters within this character set are supported.


The UK has imposed certain restrictions on Sender IDs.

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