RCS (Rich Communication Services) is a next-generation messaging standard developed by the GSMA (GSM Association) as the successor to SMS/MMS. While phone-number-based, it supports image and video sharing, group chat, read receipts, typing indicators, location sharing, and file transfers. It removes the 160-character limit and image restrictions of SMS, delivering a rich messaging experience comparable to LINE or iMessage.
RCS adoption depends heavily on Google and Apple support. Google has enabled RCS in its default messaging app (Google Messages) on Android, providing an iMessage-like experience between Android users. Apple long resisted RCS but added support in iOS 18 (2024), significantly improving the messaging experience between iPhone and Android. Previously, sending images from iPhone to Android degraded them to MMS quality, but RCS support now allows high-quality image exchange.
On the security front, RCS messages between Google Messages users support end-to-end encryption, but cross-platform messages (iPhone to Android) do not yet have encryption. This is a weakness compared to iMessage (fully encrypted between Apple devices) and Signal (fully encrypted across all platforms).
For businesses, RCS Business Messaging (RBM) enables branded messages with logos, interactive buttons, and carousel displays. Because sender verification is built in, it is also promising as a countermeasure against smishing. Legitimate RCS business messages display a brand logo and verification badge, making it easier to distinguish them from fake messages. See SMS Phishing Prevention Guide for SMS/RCS security.