Sending Messages (SFTP)

Sending messages is very simple. First, create your files in the correct file format and then transfer them to the SFTP server.

File Format

File Types JSON formatted files are supported with either the .txt or .json file extensions. Correctly formatted data is expected to process uploaded files.

Unique File Names
File names should be unique. This prevents against duplicate files as only unique file names are processed. The .zip file names don’t need to be unique.
File Extensions Only .zip .txt .json file extensions are allowed.
File Encoding Files should be encoded using UTF-8
Zipped Files We recommend zipping all .txt and .json files for size reduction and CRC checks. This is a great way to ensure that the complete file is uploaded and processed correctly.
Character Sets Before creating your files, please view our supported SFTP to SMS Character set.

File Upload

1. Log in to the SFTP Server.
2. Transfer your file to the “Send_SMS” folder.
3. Within 5 seconds, the file will be processed by SFTP to SMS automatically.
4. A file upload status will be sent to the email address specified in the file. If no email address is
specified, the account email is used.

Main Body Parameters

ParameterDefault valueRequiredDescription
Version -YesVersion number of the API to use. This allows for backwards compatibility as we update the API over time and allow for older API users to gracefully switch over to the new version.

Latest Version value is “7”
Email -NoEmail address for receiving notifications regarding whether or not the file was processed, and info if errors have occurred.
Start_DT Current TimeNoStart date and time when messages should be sent, in the format: 'YYYY-MM-DD hh:mm'. E.g: 2016-07-19 11:05 in UTC
End_DT nullNoEnd date and time when messages should complete sending, in the format: 'YYYY-MM-DD hh:mm'. E.g: 2016-07-19 11:25 in UTC
Note: Must be later than Start Delivery UTC, if provided.
SenderID FixedNoThe MSISDN the message will appear from (only available on certain accounts). Up to 11 alphanumeric characters, or 15 digits, that will be shown as the sender of the SMS.


Check_OptOuts TrueNoIf set to 'False', numbers will not be scrubbed against your opt-out list.
Message_Template -Yes, unless every contact object contains the Message field.The message template to be used for sending SMSes. The template text may contain custom fields, which are enclosed by AT signs, e.g: @@[email protected]@. This custom field will be replaced by the value in each contact object provided. The keywords value1 to value6 can be used.
Contacts -YesA collection of contacts.
Max_Errors UnlimitedNoMaximum number of errors allowed during parsing phase before the whole Send is aborted

See also