The difference between RCS vs. SMS vs. MMS: what B2C marketers need to know

SMS and MMS have served marketers well as standard promotional channels that reach customers with brief, urgent messages.

But now, a third option is making waves: Rich Communication Services (RCS). And as Apple begins to roll out RCS support for iOS 18, RCS is poised to become a major player in global messaging.

RCS offers a rich, interactive messaging experience that mirrors how today’s consumers browse and shop online. Think of RCS as a shoppable texting experience rather than as a text message.

So, what exactly is RCS? How is it different from SMS and MMS? And how should you use it as part of your mobile strategy? Let’s break it all down, so you can confidently choose the right message type for your next campaign.

What is RCS, SMS, MMS?

Before we get into strategy, here’s a quick refresher on each message type:

• RCS (Rich Communication Services): RCS allows for high-resolution media, interactive buttons, brand verification, and read receipts, all sent over mobile data or Wi-Fi.
• SMS (Short Message Service): SMS is a basic form of text message sent over carrier networks. SMS does not include other media, and it has a 160-character limit per message.
• MMS (Multimedia Messaging Service): MMS can include images, GIFs, and longer texts, and is sent over carrier networks.

With RCS now supported on both Android and iOS (starting with iOS 18), it’s positioned to become the global default messaging experience for consumers.

RCS vs. SMS vs. MMS: the breakdown

How RCS enhances customer relationships

RCS excels in cases where rich content and interactivity are key, such as product launches, promotional offers, or service interactions. But SMS remains a reliable, cost effective option for high-volume notifications like shipping updates, order confirmations, or time-sensitive alerts, where the priority is speed and simplicity.

With Klaviyo, once a customer is eligible for RCS, it’s prioritised as the preferred messaging format. This is because RCS is a better experience for both marketers and consumers. Here’s how you can get the most out of RCS to build better relationships with customers:

1. Deliver richer, high-converting content

Think of RCS as a mobile storefront. You’re not just sending a message—you’re guiding your customer through an interactive shopping experience.

RCS supports rich visuals, motion, carousels, buttons, and formatted text. You can create immersive product showcases, event promotions, or limited-time offers—all without needing a browser or app.

2. Build trust with a verified brand presence

Verified branding is a trust signal that drives opens, replies, and conversions. RCS business profiles feature your logo, brand name, and verified status, building instant credibility and reducing opt-outs.

Note that, with RCS, certain compliance features don’t take up character count, which means brands have more space for promotional experiences. For example, with RCS, there is no org-prefix required, and subscribers can opt out via a button—requirements that previously ate up precious real estate within a text.

3. Optimise performance with deeper insights

RCS gives you real-time feedback with read receipts, click tracking, and delivery confirmations. Note that Klaviyo integrates this data with fallback SMS reporting, so you get a complete performance picture across your text messaging campaigns.

With RCS, you can also send more messages in a shorter amount of time. This is because RCS is sent over data networks and therefore has much higher throughput.

4. Drive personalisation with suggested replies

Suggested replies aren’t just convenient—they’re actionable. Use them to capture preferences, gather zero-party data, and trigger reply-based flows and automations. With RCS, every reply is a signal and a conversion opportunity.

When to use RCS, SMS, or MMS in your marketing

RCS delivers a more branded, interactive, and seamless experience across campaigns and touchpoints.

There are two types of RCS message:

1. Basic RCS: Basic RCS can support all of the same SMS use cases as it has the same limitations (i.e., no media and 160 char limit).
2. Single RCS: Single RCS is any RCS message over 160 characters or one that includes rich features like cards, carousels, media, buttons, etc.

Here are some of the most common use cases for both types of RCS message:

RCS tip: RCS can reduce opt-outs because it uses a branded interface and native opt-out buttons, meaning there’s no need to waste characters on links or disclaimers. And because RCS is sent over mobile data networks and Wi-Fi, the format also supports faster, more scalable message delivery.

If a subscriber doesn’t support RCS, Klaviyo automatically falls back to SMS or MMS, ensuring full reach without fragmented threads or duplicated conversations.

How to get ready for the RCS shift

RCS is more personal and interactive than SMS and MMS, but you still won’t want to use it alone. As part of your omnichannel strategy, RCS is most effective when you’re also using email, push, social, and mobile app messaging to create consistent, channel-agnostic journeys that meet your customers wherever they are.

Also note that brands who shift their strategy and resources to accommodate RCS will gain early adopter advantage. Brands that get a head start will be in a better position to exceed customer expectations by offering the personalised brand experiences they’ve come to expect.