Zero rated short codes
Zero rated short codes are 3 to 7 digits numbers that are needed for 2-Way connection between companies and their customers. In case of zero rated short codes customers do not pay the price of the message they send to the company using it. For users it is totally free and the company pays for the cost of incoming SMS.
Zero rated short codes are used mainly for the opt-out choise as they are required in many states as a free opt-out option for end customers.
Zero rated short code also need to motivate customers to leave feedback. Often companies send SMS to end user requesting service or product ratings. In order to motivate end customers to fill out the survey and give feedback, companies stress out that the message is completely free for them.