What is the difference between an SMS Sender Identity and RCS Agent?

An SMS Sender Identity (ID) is a basic identifier (number or limited alphanumeric string) that appears on a user's phone to show who the SMS message is from. Long numbers, short codes, 10DLC, and Alphanumeric senders are examples of these. SMS is primarily for plain text messaging and a Sender ID has varying levels of brand recognition and trust depending on the type and regional support.

RCS for Business (A2P RCS), previously known as RCS Business Messaging, does not rely on phone numbers for sending messages, unlike SMS. Instead, it uses a RCS Agent. An RCS Agent is a verified and branded identity that represents a brand in an RCS messaging experience between a business and consumer. You can display one or more contact phone numbers within your RCS Agent's contact profile. This branded identity, which is visible to consumers, can also include your business's description, website, privacy policy, and terms of service.

To send RCS, a brand must go through a registration and approval process. Once approved, the brand will have this branded, verified business profile and can send messages to a user's native mobile messaging inbox, if they have an RCS-enabled device. This promotes more trusted customer communications and increased engagement. 

Unlike SMS, RCS is not directly connected to a long number or short code, but you need one to fallback to SMS if RCS is not available, and some carriers require fallback to SMS or MMS if an RCS message cannot be delivered.

For more information on RCS, visit the Sinch RCS product page.