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

SMS to un-subscribed contacts will go to status REJECTED (see How to Check SMS Logs & 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 OO 

A contact, which is globally marked as un-subscribed, 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 OO

A contact, which is marked as un-subscribed from a certain list only, will not receive any SMS from you if this list is used as a recipient. It will anyhow receive SMS from you, if it is on another list and the other list is used as a recipient or if you use the contacts phone number as a recipient manually.

That way it is possible to allow certain contacts to be un-subscribed for certain topics, types of SMS, etc. only.

Un-Subscribing contacts

Un-/Subscribe manually

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

Un-/Subscribe in bulk

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

Un-/Subscribe 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.



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