RCS in the UK: what it means for business texts

Apple's press release for iOS 18, dated 16 September 2024, says the Messages app "now supports RCS for richer media and more reliable group messaging compared to SMS and MMS". The footnote under it is the part that matters in the UK: "RCS messaging on iPhone is available in specific markets and requires support from the carrier. Users should check with their carrier for details."

Two years on, that footnote still decides whether a given customer's phone sees your message as an RCS chat or as a text, and the answer in the UK depends on which network the phone is on. CaptiFi Connect sends SMS only and does not offer RCS, so what follows is written from the outside, from Apple's, the GSMA's and the operators' own pages.

What RCS is

Rich Communication Services is the GSMA's standard for native phone messaging, published as the "Universal Profile" so that phones and networks implement the same thing; the GSMA describes its aim as "a consistent native messaging experience regardless of device or ecosystem". Ofcom's description, in a footnote to its July 2026 statement on messaging scams, is as plain as any: RCS "enables mobile users to send and receive messages over an internet connection. It offers features such as group chats, read receipts, typing indicators and support for end-to-end encryption. It supports both P2P and A2P messaging."

That first clause is the technical difference. O2's help page puts it in one sentence: "unlike SMS and MMS messages, RCS Messaging uses your data connection". A text needs a signal; an RCS message needs data or Wi-Fi, and travels through servers run by the operator or a partner. Three's help page states the consequence for its customers: "Sending and receiving RCS messages counts as data usage, the same as other messaging services", and for plans taken out after 1 October 2021 a daily roaming charge applies to RCS data used abroad.

The scale on Android is large and Google has published the numbers. At Google I/O in May 2022 it said Google Messages "already has half a billion monthly active users with RCS". By 30 November 2023 that was "more than one billion monthly active users with RCS enabled". Those are worldwide figures for one app; Google hasn't published a later count.

The GSMA has kept adding to the profile. Universal Profile 3.0, announced on 14 March 2025, added end-to-end encryption using the Messaging Layer Security protocol, which the GSMA called "the first large-scale messaging service to support interoperable E2EE", along with a richer deep link format for businesses and easier subscription management for business senders. Universal Profile 4.0, announced on 26 March 2026, added video calls started from a chat, rich text (bold, italics, strikethrough) and, for businesses, Rich Cards that can stream video and more control over whether a link opens in the chat or in an app. Universal Profile 4.1, on 28 July 2026, refined the encryption specification after interoperability testing and changed the transport layer, with no new consumer features.

iPhone: iOS 18 plus a network that has switched it on

Apple's support page for RCS (published 25 May 2026 in its UK edition) sets two conditions: "To use RCS, you need iOS 18 and a mobile data plan from a network provider that supports RCS messaging on iPhone." If the setting isn't there, "RCS messaging may not be available", and "Availability varies by region and network provider." The same page describes a separate switch, "Turn RCS Business Messages on or off", with the note that "Some businesses can send alerts and updates about your orders and other transactions through RCS messaging."

Two more details from Apple's pages shape how a message looks on an iPhone. RCS messages, like SMS, appear in green bubbles, so the colour tells a customer nothing about which one they received. And on encryption, Apple is careful: "RCS messages can be end-to-end encrypted when all participants have network providers that support encryption"; otherwise "your RCS messages aren't protected from a third party reading them". Encrypted RCS arrived as a beta in iOS 26.5, on by default where the network supports it.

So which UK networks do? Apple keeps a list of network provider features for iPhone, and the version published on 18 September 2026 gives this for the United Kingdom.

The operators' own pages fill in the dates. EE: "available on iOS 18 and above". Three: "RCS is automatically enabled on all compatible devices on iOS 18.2 onwards." O2, in a help article last updated on 14 February 2025: RCS works on "all Android devices supporting Android 5.0 or above and all iPhones supporting iOS 18.2 or above". Vodafone has no RCS entry on Apple's list, and its own guidance for customers moving over from Three after the two companies merged puts it bluntly: "If you move from Three to Vodafone and use an iOS device, RCS (Rich Communication Services) messaging will no longer be available. Your phone will automatically use SMS or MMS when messaging Android users."

On an iPhone on Vodafone, or on any of the five providers Apple doesn't list, the message from an Android friend arrives as a text, and so does the message from a business.

What RCS would change for business texts

The business side of RCS, which the industry calls RCS Business Messaging, is what the GSMA's Rich Cards and link controls are for: a message with a logo, an image, buttons and a card the customer can tap, rather than 160 characters. EE's help page gives the everyday version: businesses "can send updates such as event tickets, boarding passes, and appointment reminders". Apple's is "alerts and updates about your orders and other transactions". O2's page, as of February 2025, puts its own business messaging in the future tense: "We're working with many companies to make it easier for you to get in touch with them through RCS Messages."

The question for a UK business is how many of its customers would see any of that. Start with the phone. Ofcom's 2025 survey of 2,058 smartphone users put Android at 60% and iOS at 40% overall, with a steep age gradient: 65% of 16 to 24 year olds had an iPhone, against 31% of 55 to 74 year olds.

Then apply the conditions. An Android user needs Google Messages (or another RCS client) with RCS on and a data connection. An iPhone user needs iOS 18 or later, one of the six providers on Apple's list, the RCS setting on, and the separate business messages setting on. Every customer who fails any one of those tests gets SMS instead, and the network does the swap on its own. EE's wording: if the conditions aren't met, "your message will automatically send as an SMS or MMS instead". O2's: "The Messages app will automatically switch to using SMS/MMS as long as you have a network connection." The GSMA built the same assumption into Universal Profile 4.0, which includes "prompting users to review plain-text versions when a rich text message must fall back to SMS".

This is why SMS is still the floor. A business messaging product that sends RCS has to carry a plain text version of every message for the customers who can't receive the rich one, and in the UK in 2026 that is a large share of them: everyone on Vodafone with an iPhone, everyone on the unlisted providers, everyone with an older iPhone, everyone who turned the toggle off, and everyone whose phone is in a signal black spot with no data. The text has to work on its own, which means the 160-character discipline, the sender name at the front and the one clear action still apply, whatever sits on top. Our guide on how business texts reach UK phones describes the SMS route itself.

There's a regulatory loose end as well. Ofcom's July 2026 statement says that whether an RCS service "is now, or could in the future be, regulated under the Communications Act will depend on how it is implemented in the UK", and that "It is for operators to determine in the first instance" whether their RCS counts as a regulated messaging service. Its consumer research, meanwhile, counts suspicious texts received "via SMS/RCS and/or iMessage" as one category, because from the customer's side they arrive in the same app. The scam rules Ofcom finalised that month apply to messaging services regulated under the Communications Act; how far they reach into RCS is a question Ofcom has left with the operators for now.

What to do about it

For most UK businesses sending reminders, confirmations and updates, the practical answer in 2026 is to carry on writing texts that work as SMS, because that is what reaches every customer. Keep each message to one part where you can (the SMS character limit guide has the arithmetic), use a sender name customers recognise, and put anything rich on a web page behind a link rather than in the message. A customer on an RCS-capable phone sees exactly the same text as one who isn't; nothing is lost by not sending RCS, and nothing you send as SMS needs a fallback.

If your customer base is young and on the right networks, RCS Business Messaging from a provider that offers it may be worth a trial for marketing messages where a card with an image earns its place. Check what share of your list is on iPhone and on which networks before paying for it, and read the fallback terms: the SMS version is the one most of your list will get, and it has to be written as a text in its own right.

CaptiFi Connect sends SMS to UK mobiles, with delivery reports per text, and does not offer RCS. A text sent through it arrives in the same green bubble as an RCS message would, in the same Messages app, on every phone on every UK network, including the five providers that Apple's September 2026 list leaves out.