To make sure a contact will not receive any SMS from you, we recommend to use our opt-out (OO) system.

SMS to unsubscribed contacts will go to status UNSUBSCRIBED (see How to Check SMS Logs and Status).

Each contact has an OO flag that is either active (no SMS will be sent to this number) or inactive.

There are 2 different types of OO flags on SMS.to: Global (see green marker below) or List (see red marker below).


Global Opt-Out 

A contact, which is globally marked as unsubscribed, will never receive any SMS from you, no matter which method is used to send it (sending to a list, sending a single SMS, etc.).

By default, each opt-out request is interpreted as a global OO.

List Opt-Out

A contact marked as unsubscribed from a specific list will not receive any SMS if that list is used as a recipient. However, they will still receive an SMS if they are on a different list (used as a recipient), or if you manually use their phone number as a single recipient. 

This allows you to selectively unsubscribe contacts from specific topics or types of SMS.

Un-Subscribing contacts

Unsubscribe manually

In order to manually subscribe or unsubscribe a contact, click on the corresponding OO flag next to the contact and confirm your action:

Unsubscribe in bulk

Select one or more contacts from the table view and choose the required action from the menu above the contact table:

Unsubscribe triggered by the contact

We offer several methods, which allow you to leave it up to the recipient of the SMS to decide, whether he wants to opt-out of your traffic allowing you to comply with GDPR, for example:

  • opt out via link
  • opt out via TFN (toll free number)

Please see How to use Opt-out Feature for more details on this topic.


Unsubscribing is not a real-time feature. Actions may take up to 24 hours to come into effect. 



If you have any questions, please send an email to support@sms.to