It is mandatory to get consent from a mobile phone user to send them text alerts. If your mobile phone users have already consented previously through a different platform or option, you can start sending them regular text alerts. If they haven't consented previously, here are some recommendations.

Create a keyword auto-reply

1. Click here to view our keyword auto-reply guide.
2. Once you're familiar with creating a keyword auto-reply, create a keyword auto-reply that uses the "Yes" tag. 
3. Add an auto-reply to the "Yes" tag such as "Thank you for opting-in to our SMS Company."
4. Send a text alert to the mobile phone users that need to opt-in, such as "Reply 'Yes' to opt-in a receive messages from SMS Company"
5. The mobile phone users that reply "Yes" will get added to the "Yes" tag created in step #2.
6. You will then be able to send regular text alerts to mobile phone users under the "Yes" tag since you now have their consent.