RCS (Rich Communication Services) is the GSMA’s IP messaging profile meant to succeed SMS/MMS feature-for-feature while adding capabilities those PDUs cannot carry: typing indicators, read receipts, high-resolution media, reactions, and, for business messaging, verified branding and suggested actions. The interoperable consumer spec is the GSMA RCS Universal Profile. It runs over the mobile network’s IP path, not as a 140-byte SMS PDU.
Google’s Jibe Cloud has historically been the hub many MNOs and Google Messages clients interconnect through. Carriers that did not stand up their own RCS application server pointed at Jibe. That is an industry deployment fact, not a GSMA requirement. Other hubs exist; Jibe is the one most Android users were connected to during the 2018-2025 period.
Apple RCS in iOS 18
Apple shipped RCS in iOS 18 (2024) using the GSMA Universal Profile for cross-platform texting with Android. That implementation is a texting interoperability feature: it replaces some green-bubble SMS / MMS legs between iPhone and Android with RCS when both sides and both networks support it. Read receipts and typing indicators can appear in those threads. It is not iMessage, it does not turn the thread blue, and it is not Apple Messages for Business (the separate Apple business-messaging program).
RCS Business Messaging (RBM) on Android (verified sender, branding, suggested replies, rich cards) is a distinct A2P product. iPhone RCS in iOS 18 does not mean the iPhone supports RBM. A brand that is live on Google RBM is not automatically live in Apple Messages for Business or as a branded RCS agent on iPhone.
RCS vs SMS vs MMS vs iMessage
| SMS | MMS | RCS (Universal Profile) | iMessage / Messages for Business | |
|---|---|---|---|---|
| Standards body | 3GPP / GSM | 3GPP | GSMA Universal Profile | Apple proprietary |
| Transport | SMSC store-and-forward | MMSC + data retrieve | IP (carrier RCS / Jibe-style hub) | Apple servers (blue bubble) |
| Read receipts / typing | No (not in the SMS spec) | No | Yes, when both clients enable them | Yes, inside Apple’s network |
| Branding for A2P | Number or CNAM-like sender ID only | Same | RBM: verified brand, logo, rich cards (where RBM is supported) | Messages for Business: separate Apple onboarding |
| Apple iPhone | Yes | Yes | Consumer RCS from iOS 18 (texting with Android), not RBM-as-iMessage | Native |
| Fallback | N/A | Sometimes SMS + URL | Falls back to SMS/MMS when RCS is unavailable | Falls back to green SMS/MMS (or RCS to Android on iOS 18+) |
A2P on RCS
Where RBM is available, A2P can move off concatenated SMS into branded sessions. That does not retire 10DLC for the SMS fallback, and it does not replace TCPA consent for US marketing. Coverage depends on the combination of client (Google Messages, iOS RCS, carrier app), hub, and MNO. Until that coverage is universal, SMS remains the lowest-common-denominator A2P bearer.