RCS vs SMS: what is RCS messaging and how does it work?

What is RCS messaging?

RCS, short for Rich Communication Services, is a messaging standard that adds modern chat features to the default messaging app on a phone. Think typing indicators, high-resolution images, read receipts, group chats and, for businesses, verified sender profiles with logos, buttons and swipeable cards. It is often described as SMS with the features of a chat app.

For a business, RCS Business Messaging (RBM) is the part that matters. A brand registers an agent, which is its verified profile. The customer sees the company name, logo and a verification mark, then a message they can read, tap and answer without installing anything. The standard is maintained by the GSMA, the mobile operators' association, and Google runs the largest RCS service through Google Messages and its RCS Business Messaging platform.

If you run SMS today, the practical question is not RCS or SMS but how to use both. This guide explains how RCS works, where it beats SMS, where it does not, and how fallback stops you losing the customers whose phones cannot receive it. Our RCS product page shows how we put this together.

RCS vs SMS: the differences that matter

Two of these rows decide most projects. Reach says SMS remains the only channel that arrives on every handset. Interactivity says RCS can turn a message into a small app: a customer can confirm a delivery slot, open a map or pay, without leaving the thread.

How RCS works behind the scenes

A message reaches a customer in four steps, and the second one explains why fallback is not optional.

1. You send a request to the platform. Your application calls an API with the recipient, content type and your agent. The same API can send SMS, so one integration covers both. See the API reference.
2. The platform checks capability. It asks whether the recipient's phone and carrier support RCS for business messages right now. The answer can change: a person can switch data off or change phone.
3. RCS is delivered, or SMS takes over. If the phone is capable, the message goes by RCS. If not, the platform sends an SMS version, which is why you write both.
4. Events come back. You receive delivered, read and tap events, and incoming replies, as webhooks. Handle them as you would SMS receipts.

Behind this is the Universal Profile published by the GSMA, which defines the features every RCS client should support so that messages look the same across phones and carriers. Different operators have adopted it at different speeds, so coverage varies by country.

What RCS messages can contain

• Text with suggested replies. Up to 3,072 characters, followed by tappable answers such as Yes, No, Reschedule.
• Standalone rich cards. An image or video, a title, a description and up to a few buttons in a single card.
• Carousels. A row of cards a customer can swipe through. Good for product choices or appointment slots.
• Actions. Buttons that open a link, dial a number, show a location on a map, add a calendar event or share the customer's location.
• Receipts and typing indicators. You can see when a message was read, which SMS cannot show.

Rich cards use images, so budget for file size and test on slow connections. Alt text and plain wording help accessibility, and it is good practice to keep the plain SMS version complete in itself, since that is what some recipients will see.

When to use RCS, and when to stay with SMS

See also our marketing and transactional messaging solutions for patterns in each case.

RCS in India and other markets

RCS Business Messaging is strongest where Android is dominant, and India is a major example. Google Messages is the default messaging app on a large share of Android phones sold there, and the main operators support business messaging through it. In the UK and parts of Europe, carriers have also rolled out RCS, and in the United States all major carriers support it. On iPhone, RCS support arrived with iOS 18 for conversations with Android phones, and business messaging coverage there has been expanding, so check the current position for the audience you target.

What does not change from country to country is the approval path: a verified agent, a carrier launch review and, for some operators, restrictions on content categories. Plan for a few weeks of setup before the first campaign, and expect India to ask for brand documents that match your DLT registration.

How to send your first RCS message

Create the agent first, because approval takes longest. Once it is live, the sending call is short. This example sends a card with two buttons and a fallback text:

{
  "channel": "rcs",
  "to": "+919812345670",
  "agent": "telnxo-demo",
  "card": {
    "title": "Your parcel is on its way",
    "text": "Arriving today between 2 and 5 pm.",
    "buttons": [
      { "type": "reply", "label": "Reschedule" },
      { "type": "url", "label": "Track", "url": "https://example.com/t/4821" }
    ]
  },
  "fallback": { "channel": "sms", "text": "Your parcel arrives today 2-5 pm. Track: https://example.com/t/4821" }
}

Treat this as an illustration of the shape of a call; field names are listed in the API reference and may differ from other providers. Run a small test to a group of staff with different phones and carriers, and compare how each handset renders the card.

Measuring results

Read receipts and taps are the first things teams notice, and they tempt people to compare RCS read rates with SMS. That comparison is not fair, because SMS cannot report reads at all. A better test is business outcome: confirmed deliveries, completed payments or reduced support calls, measured for a group that gets RCS with fallback against a group that gets SMS only. Our analytics report both groups from the same dashboard.

Use RCS to improve the message, and SMS to make sure the message arrives.

Next steps

If you are new to messaging, start with SMS and understand how delivery works through our guide to the SMS gateway. Add WhatsApp where your customers already chat, and RCS where branded cards will improve results. All three share one API and one set of delivery events with us. For pricing, see our pricing.