Short answer
RCS business messaging (RBM) lets a verified brand send branded, interactive messages to a customer's default messaging app, such as Google Messages. Messages can carry the brand's name and logo, rich cards, carousels, media and suggested replies. RBM works only where the carrier and device support RCS, so businesses keep SMS as a fallback.
How does RCS business messaging work?
RCS (Rich Communication Services) is the GSMA standard that upgrades native phone messaging beyond SMS. RBM is its business side. In Google's model, a partner builds an RBM agent, the brand's verified sender, and sends messages to phone numbers through Google's RBM API as HTTP requests with JSON payloads.
User replies and events arrive at the partner's webhook. If a number is not RCS-capable, the API returns an error and the business should send the message through another channel, usually SMS.
What can an RCS business message contain?
Google's documentation lists these building blocks. Every message comes from the agent, which shows the brand's name, logo and a verification checkmark in Google Messages after launch.
| Element | What Google's documentation allows |
|---|---|
| Text | Up to 3,072 characters |
| Rich card | Media, title, description and up to 4 suggestions in the card |
| Carousel | 2 to 10 rich cards the user swipes through |
| Suggestions | Up to 11 reply or action chips per message |
| Media and PDF | Files up to 100 MiB |
What does a business need to start?
- Choose an RBM partner, which creates the agent with its name, logo, hosting region, billing category and use case (OTP, transactional, promotional or multi-use).
- Test the agent on registered test devices, including the STOP opt-out flow.
- Submit brand verification and a launch request for each country and carrier.
- Plan SMS fallback for recipients without RCS, and confirm carrier availability in every target market.
Limits to plan for
Reach is the main limit: RBM depends on carrier launches and device support in each country, and availability in the GCC varies by operator. OmniChannels.ai, through BroadNet as a Google RBM partner, offers verified branded senders, rich cards, carousels, suggested replies and automatic SMS fallback.