An SMS Gateway allows a computer to send and receive SMS messages to and from a mobile device. Via a telecommunications network. An SMS Gateway, at its simplest, is a website that allows you to send text messages to contact lists via a telco. The SMS Gateway can then receive any replies. There are two main ways computers interact with SMS Gateways. Through an Online SMS Gateway via a website/dashboard or via an SMS Gateway API.

SMS Marketing is when businesses spread permission-based (Opt in) promotional messages by text. Examples of SMS Marketing are a restaurant promoting 50% off main meals on a specific night. A fashion store inviting you to a VIP night, a gym letting you know a new class is available. Most SMS Marketing is done via dashboard in the form of bulk SMS. All SMS Marketing messages must have an Opt-out function at the end of the message. Generally in the form of Reply STOP.

Transactional SMS is generally all business text messages that aren’t marketing or promotional.They are functional or informational text messages. About a product or service that a customer has engaged with. Examples of Transactional SMS are a dentist surgery reminding you of an appointment. An auto centre reminding you your car is due for a service. A delivery service saying a parcel is out for delivery. Transactional SMS messages can be consistent in their content and done at scale. So businesses will generally use an SMS Gateway API to automate the process. Transactional SMS messages are not required to have an opt-out message.