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 web client of Google Messages or via Microsoft Phone Link.
Google Messages was the first client to offer end-to-end encryption (E2EE) over RCS. E2EE using Messaging Layer Security (MLS) was added to the RCS standard in March 2025. As of May 2026, the GSMA standard for E2EE is in rollout for Google Messages and Apple Messages.
Branding RCS is also marketed as Advanced Messaging and 5G Messaging (in China); it was previously variously marketed as chat features, enhanced chat, joyn, and SMS+. These should not be confused with SMSoIP, enabling SMS over all-IP infrastructure such as modern LTE and 5G deployments.
Software support
Samsung Electronics was one of the first major device original equipment manufacturers (OEMs) to support the RCS initiative and it commercially launched RCS capable devices in Europe in 2012 and in the United States in 2015. Following the launch of the new RCS Universal Profile specification, Samsung supported it on new devices since 2017 in its stock Messages app. In December 2020, Samsung updated its One UI Messages app to also allow users to opt into RCS using Google's Jibe backend instead of carriers in certain regions.
The Samsung Messages client brands the RCS capability as chat features, and displays Enter chat message in the message box. Starting in 2024, Samsung Messages was no longer coming preinstalled on Galaxy phones sold in the United States in favor of Google Messages. In January 2025, the app was removed from the Google Play Store while remaining functional for existing users. However, development later resumed and RCS capability was re-added. Samsung Messages was subsequently discontinued in the United States on July 6, 2026, for devices running Android 12 and later, with Samsung directing users to migrate to Google Messages.
Mobile phones running Android with Google Play Services support RCS with its native messaging app, Google Messages, beginning with Android Lollipop. In June 2019, Google announced that it would begin to deploy the RCS on an opt-in basis via the Messages app. This service was compliant with the Universal Profile and hosted by Google Jibe if the carrier does not provide RCS, which is also known as the Google Guest program. Google began the discontinuation of Google Guest in 2025. Before 2023, the Google Messages app branded RCS communication as Chat, before it was renamed to RCS to be clearer. In March 2024, it was reported that Google was "silently" blocking RCS on rooted Androids.
Other Android powered devices such as Huawei's HarmonyOS in China also support RCS through native messaging clients (EMUI version 8.1+).
In June 2024, Apple announced that support for RCS would be added to the Messages app in iOS 18; as with SMS, RCS is displayed with green message bubbles and buttons, although an RCS indicator is displayed in the message composer text field. iOS 18 launched with support for RCS in September 2024.
Commercial deployments
+Commercial RCS DeploymentsRegionBackendAppPlatformEnd-to-End EncryptionNotes🌐 GlobalGoogle JibeGoogle MessagesAndroidYes (via Messaging Layer Security (MLS) standard support rolling out as of May 2026. Previously, via custom extension using Signal protocol)While Google initially provided RCS indiscriminately to all compatible Android phones without implicit carrier support, this is not the case anymore.Messages (Apple)iOS 18+Yes (via Messaging Layer Security (MLS) standard support, starting from iOS 26.5)E2EE support is only enabled if a carrier supports it in its iOS Carrier Bundle. Samsung MessagesAndroidDiscontinued in the United States on July 6, 2026, with Samsung transitioning users to Google Messages. The app still remains available in other regions. JioSandesh Messages (Apple)Android, iOSJio does not connect to global RCS network.Synchronoss +MessageAndroid, iOSKDDI, NTT DOCOMO, and SoftBank. Does not connect to global RCS network.Starting from 2025, KDDI has encouraged subscribers to migrate away.ZTEMultiple native messaging clientsHarmonyOS, HyperOS, iOS 18+Samsung Galaxy Chatting+ Messages (Apple)Android, iOSJoint initiative between Samsung Electronics, KT, SKT and LG U+.
Development and history
Launch and "joyn" The Rich Communication Suite industry initiative was formed by a group of industry promoters in 2007. In February 2008 the GSM Association (GSMA) officially became the project home of RCS and an RCS steering committee was established by the organization, officially announced as Rich Communications Suite on 15 September 2008, later known as Rich Communication Services. The companies involved in launching it were: operators Orange, Telecom Italia, Telefonica and TeleSonera, network vendors Ericsson and Nokia Siemens Networks, and device vendors Nokia, Sony Ericsson and Samsung. The steering committee specified the definition, testing, and integration of the services in the application suite.
By 2010, RCS had released Version 4 of its specification, however progress was slow and it had yet to be deployed on commercial subscriber services. During this time, closed internet-based instant messaging services (known in the industry as "OTT" (over-the-top) providers) were rising in popularity. To accelerate development, the RCS project released a new specification – RCS-e (e = "enhanced"), which included various iterations of the original RCS specifications. At Mobile World Congress 2012, RCS-e was launched under the consumer brand name "joyn" (a brand that has since been abandoned). The full list of carriers that agreed to support RCS-e at the time were AT&T, Bell Mobility, Bharti Airtel, Deutsche Telekom, Jio, KPN, KT Corporation, LG U+, Orange, Orascom Telecom, Rogers Communications, SFR, SK Telecom, Telecom Italia, Telefónica, Telia Company, Telus, Verizon and Vodafone. That year, the first RCS-e/Joyn services were rolled out by networks in Spain, Germany and the US.
However, the RCS standard struggled with fragmentation and incompatibility, with one industry analyst stating in 2015 that the project was a "zombie [...] infected with bureaucracy, complexity, and irrelevance". A Mountain View-based startup called Jibe Mobile, headed and cofounded by Iranian-American engineer Amir Sarhangi, attempted to solve the situation having built an in-house cloud platform claimed to be fully RCS interoperable between carriers, and offering a fast deployment of the service to the carriers. Some operators like Orange and Deutsche Telekom had previously signed up to the Jibe cloud platform.
Universal profile Google purchased Jibe Mobile in September 2015, and Amir Sarhangi led the RCS project at Google. Subsequently Google Jibe worked together with the GSMA which led to the creation of the Universal Profile standard. The GSMA published the Universal Profile in November 2016. The Universal Profile is a single GSMA specification, and carriers that deploy the Universal Profile makes interconnection with other carriers possible, designed to help carriers launch RCS quickly and scale easily.
The new standard, helped by promotion from Google, finally led to RCS taking off: in early 2017, there were 47 mobile network operators, 11 manufacturers, and 2 OS providers (Google and Microsoft) that had announced their support of the Universal Profile. To accelerate adoption, Google transferred the team that was working on Google Allo to work on a wider RCS implementation, then in 2019 it launched the Google Guest program to provide an OTT (over-the-top) RCS solution using Jibe to all Google Android users for person-to-person (P2P) traffic without requiring carrier support. Google Guest rolled out globally by 2020. Google began the discontinuation of Google Guest in 2025. Google Guest was not used for RCS Business Messaging (RBM).
Adoption In October 2019, the four major U.S. carriers announced an agreement to form the Cross-Carrier Messaging Initiative (CCMI) to jointly implement RCS using a newly developed app. This service was to be compatible with the Universal Profile. However, this carrier-made app was never implemented, and RCS via Google Guest and Google Jibe in Google Messages was rolled out by 2020. By 2021, both T-Mobile (now merged with Sprint) and AT&T signed deals with Google to adopt Google Messages. In 2023, T-Mobile and AT&T agreed to use Google Jibe directly to implement RCS services, and in 2024 Verizon agreed to use Google Jibe directly, an alternative to both self-implemented RCS and Google Guest. Google began the discontinuation of Google Guest in 2025.
While playing a key role in the growth of RCS in most markets, Google services are banned in China. The three Chinese carriers together announced in April 2020 that they will roll out RCS, branded as 5G Messaging. Both China Telecom and China Unicom had rolled out the services within two years time. However, China Mobile, the country's and also world's largest mobile carrier, delayed the roll-out until it began in December 2023. In 2020, Germany's three carriers had all rolled out RCS services, interconnected and provided by Mavenir; Mavenir's RCS network also started powering carrier Rakuten Mobile in Japan, however this network is not linked to the RCS network used by Japan's three largest carriers, who use their own network named +Message that is currently not based on the Universal Profile specifications and not connected to the global RCS network.