SMS carriers worldwide support automatic functions for end-users based on specific keywords.

The keywords and functions are managed at the carrier level and are permanently active.  

Opt-in keywords

The following keywords automatically unblock the number sending the keyword from receiving further messages from the number to which the keyword is sent.

• START
• UNSTOP

Carrier keywords are non-case-sensitive. 

Only the keyword by itself will unblock the phone number.  Replying "Please Unstop" or "START PLEASE" will not.

Confirmation messages

The carrier will send one of the following messages to the end user confirming the opt-in, depending on the outbound and/or inbound number. 

Default Reply Example 1:

Msg&data rates may apply. Reply HELP for help, STOP to cancel

Default Reply Example 2:

You have successfully been re-subscribed to messages from this number. Reply HELP for help, Reply STOP to unsubscribe. Msg&Data Rates May Apply.

These messages are sent directly from the carrier.  There is no charge, and they do not appear in Sakari messaging reports.

Sakari support

When an opt-in keyword is received by a number dedicated to a Sakari account, the contact record for the number from which the keyword is received is unblocked.

All subsequent message attempts will be sent to the carrier, and the message will display in Sakari.

Sakari opt-in support is limited to unblocking system-blocked contacts in Sakari.  It is the responsibility of the brand or business from whom the messages are sent to ensure opt-in is collected in a compliant manner before messaging for marketing and/or transactional types of message.