Rich Communication Services

Rich Communication Services (RCS) is a communication protocol standard for instant messaging, primarily for mobile phones, developed and defined by the GSM Association (GSMA). It is a replacement of SMS and MMS on cellular networks with more modern features including high resolution image and video support, typing indicators, file sharing, and improved group chat functionality. Development of RCS began in 2007 but early versions lacked features and interoperability; a new specification named Universal Profile was developed and has been continually rolled out since 2017. RCS has been designed as an industry open standard to provide improved capabilities over basic text messaging, based on the Internet Protocol (IP). Its development has also been supported by mobile network operators to remain relevant in customer experience in response to over-the-top (OTT) chat apps and services. Additional features of RCS include presence information, location and multimedia sharing, video calling, and operation over mobile data or Wi-Fi, natively integrated in mobile phones without requiring the download of third-party apps. As of 2020, RCS had rolled out across 90 cell operators in 60 countries globally, and had an estimated 2.5 billion monthly active users as of 2024. The Google Guest program formerly provided person-to-person (P2P) RCS in Google Messages on Android when a carrier does not provide RCS, provided via the Google Jibe backend. However, Google began the discontinuation of Google Guest in 2025. Alternatively, RCS service may be provided by a carrier directly; by 2025, carrier partnerships with Google Jibe for direct service have become common. Providing direct RCS service allows for support of additional clients such as Apple Messages, and enables carriers to make the additional choice of providing RCS Business Messages (RBM). Apple added support for RCS in Messages with iOS 18 in September 2024; RCS is also accessible through desktops via the...