A typing indicator is the animated dots showing that the other side is composing a message. RCS supports it in both personal and business chats; SMS and MMS have no equivalent.
How it works in RCS
The indicator is a small status event carried by the RCS protocol alongside read receipts. In a personal chat it shows while the other person types. In a business conversation, an RBM agent can send the same "composing" event on purpose, so a customer waiting for a chatbot or a live agent sees that a reply is coming rather than a silent thread. The RBM API exposes it as an event the agent sends before its message.
Why a business would bother
Two reasons. Perceived responsiveness: a two-second pause with dots feels attended; a two-second pause without them feels ignored. And pacing: an RCS chatbot that answers instantly with three messages in a row reads as a machine, while one that shows a brief typing state before each reply reads as a conversation. Keep it honest; showing typing while nothing is being prepared is the messaging equivalent of hold music.
Where it does not appear
Messages that fell back to SMS carry no indicator, and iPhones only show RCS indicators since iOS 18.1. It is a feature of the conversation view, not of a broadcast.