SMS double opt-in for historical contacts

See also: Double opt-in for SMS

If you have contacts in a market that requires double opt-in for SMS, those contacts can only enter your SMS campaigns if they have double opted-in.

There are two ways to double opt-in your existing contacts, i.e. those who were already single opted-in.

Double opt-in via SMS campaign

To send a double opt-in link to your existing contacts, set up an automation campaign and include the {{ double_optin_url }} merge tag in the SMS text:

You must check the Send as transactional flag for these sends. 

This will make sure your SMS reaches your contacts regardless of double opt-in requirements.

Double opt-in via CSV

If your contacts previously double opted-in through another system, you can update their opt-in status via CSV upload. 

Include the header channel_sms_marketing_optin_level in your CSVs, and enter "double" for double opt-in: