Common DLT Errors in SMS Campaigns and Their Solutions

Template Mismatch Error

One of the most common issues occurs when the SMS content does not exactly match the DLT-approved template. Telecom operators strictly verify the message content with the registered template. Even small differences such as extra spaces, punctuation changes, or modified wording can cause the message to be rejected.

Solution:

Always ensure that the SMS content sent through the panel or API matches the approved DLT template exactly. Avoid editing the message once the template is approved.

Incorrect Sender ID

Another frequent error happens when businesses use an unregistered or incorrect Sender ID (Header) while sending SMS campaigns. Since sender IDs must be approved on the DLT platform, using an invalid header can lead to message rejection.

Solution:

Make sure that the sender ID used in the campaign is properly registered and approved on the DLT platform. Also verify that the same sender ID is passed in the API or SMS panel.

Missing Template ID in API

When sending SMS through an API, businesses must include the DLT Template ID in the request parameters. If the template ID is missing or incorrect, the message may fail to process.

Solution:

Always include the correct template ID in the API request. This helps telecom networks validate the message against the approved template.

Unwhitelisted URLs

SMS messages containing links may be rejected if the URL has not been whitelisted on the DLT platform. Telecom systems check whether the links used in SMS campaigns are approved.

Solution:

Ensure that all URLs included in SMS templates are properly whitelisted on the DLT portal. If URL shorteners are used, the base domain should also be whitelisted.

DND or Consent Issues

Promotional SMS messages cannot be delivered to numbers registered under DND (Do Not Disturb). If businesses attempt to send promotional messages to these numbers, the messages will fail.

Solution:

Use proper consent management and send promotional SMS only to customers who have opted in to receive marketing messages.

Avoiding DLT Errors

By maintaining correct template content, approved sender IDs, valid template IDs, and proper URL whitelisting, businesses can avoid most DLT errors in SMS campaigns. Following these compliance guidelines ensures better message delivery and a smoother SMS campaign experience.