Do I need to have written authorization from customers to send SMS?

In order to send a message to a specific cell phone number, as a Pony Express user you need the permission of the cell phone number owner.  A mobile phone owner must give their explicit permission to you indicating they wish to receive messages from you. 

There are a number of ways you can get authorization to send messages.

We generally recommend the following two ways: 

1. Keywords: For instance, Shmuel uses his Pony Express phone number and the keyword "weekend". A user can send a message to the phone number with the text message "weekend".  The user then opts in to join Shmuel's customer database, which allows him to then send user future texts regarding special events or promotions they may have.
2. Physically written authorization:  In certain use cases it best to get their customers written permission, especially businesses who have regular or walk-in customers.  For instance, a dealer may include a checkbox on the bottom of a new customer information form that just says “I would like to receive special discount information via text message”. 

Feel free to contact support if you need further assistance regarding collecting user permissions.