RCS Is the New SMS: The Ecommerce Guide On What to Send & How to Design a Fallback

Plain text had a good solo run, but now that run is over.

Rich Communication Services (RCS) is an upgrade to SMS that delivers branded, interactive, media-rich messages—think images, carousels and tap-to-buy buttons—directly in your subscribers’ native text inbox. And now, approximately 70% of US smartphones are RCS-capable.

After iOS 18 launched in 2024, RCS messages gained a ton of traction, with business messaging volume surging 1,400%. Last year alone, global RCS business traffic hit 50 billion messages, up 50% year-over-year. 

For ecommerce marketers already running SMS, RCS delivers to the same inboxes and offers the same fallback infrastructure. With these branded messages though, richer media and interactive elements tend to convert 3–7X better than plain text. If you need to get started with RCS or even get caught up, here's your decision framework for when to adopt, what to send and how to stay compliant.

What is RCS?

Think of RCS messages as SMS with a more modern UI. Thoughtfully designed messages are delivered the same native text inbox, using the same phone number-based delivery, but rebuilt for how people actually use their phones for entertainment in 2026. They’re branded and all around more engaging to look at.

Here's what’s different with RCS, compared to SMS:

• Verified brand sender: You can include your logo, name and a verification badge in messages.

• Inline rich media: Messages contain images, video and GIFs up to 100 MB with no compression, making for a more immersive subscriber experience.

• Rich cards + carousels: RCS offers 2–10 swipeable product cards with images, copy and buttons.

• Interactive CTAs: Messages can contain tappable buttons like "Shop Now," "Track Order" or "Claim Offer."

• 3,072 characters: This is a major upgrade from SMS's 160 character limit, which means no truncated messages are delivered.

• Read receipts and typing indicators: RCS boasts the delivery confirmations that SMS never had.

• Automatic fallback: If the recipient's device doesn't support RCS, they’re auto-delivered as SMS/MMS, with no action required on your end.

This fallback behavior is what makes RCS low-risk to adopt, as your core message will still be deliverable to all subscribers.

RCS vs. SMS At a Glance:

When to Send RCS vs. SMS

When determining which message type to send, the smartest approach is the waterfall model: Attempt RCS first, then fall back to SMS automatically. 

Still, creative investment requires a real decision about which moments are worth the upgrade. Weigh the following points below to determine if RCS or SMS is better for your next campaign.

Use RCS for:

• Cart abandonment:  RCS reduces cart abandonment by ~20% vs. a plain text reminder. Show the actual abandoned product as a rich card with images, its price and a one-tap "Complete Purchase" button.

• Product launches and promotions: Carousels turn a text message into a swipeable mini catalog. Nespresso used RCS carousels for holiday products and saw 2x the click rate vs. their SMS campaigns.

• Re-engagement:  Visual experiences reactivate audiences in ways that plain text can't. For example, Spanx tested RCS against SMS for previously unengaged subscribers and saw +236% CTR and +190% conversion rate.

• Post-purchase cross-sell: Deliver swipeable recommendations to their text inboxes. Campaigns such as "you may also like . . ." and interactive order tracking all keep customers in the loop and buying more.

• Loyalty and VIP updates: Personalization accompanying a branded, visually polished experience reinforces the premium feel that loyalty programs are supposed to deliver.

Stick with SMS for:

• One-time passwords and authentication: These are standard messages with universal delivery required.

• Time-critical alerts: If guaranteed delivery matters more than engagement, such as a message that a shipment is on the way or delayed, opt for SMS.

• Tight-budget sends: RCS rich messages run 20–50% above SMS on cost per message, so consider sticking with SMS if you’re on a more rigid budget.

RCS Creative Specs: The Reference Sheet You'll Actually Use

RCS creative has hard technical requirements that ecommerce email marketers and designers often have to hunt down across different blogs, manuals and reference sheets. Bookmark this page to easily come back to, as these specs come from Google's official RCS for Business documentation.

Quick-Reference RCS Spec Sheet

3 RCS Fallback Copywriting Rules

1. Write your SMS fallback first: This practice forces messaging discipline and ensures every version communicates real value, without relying on visuals.

2. Every RCS CTA button needs a URL equivalent in the SMS fallback: Don't lose conversion paths when rich elements strip out.

3. Keep your SMS fallback under 160 characters: This avoids segment splitting, which drives up cost and dilutes your message.

3 Common RCS Mistakes to Avoid

• Carousel copy that truncates badly: Titles cut off at 24 characters in a carousel’s scroll view. Avoid this by always testing on a real device before sending.

• Skipping the SMS fallback preview entirely: If your messaging platform doesn't auto-preview the fallback, manually QA it every time. (See the previous point.)

• Using a hero image that’s optimized for email: Hero images for email don’t translate to texts, as they’re the wrong aspect ratio and often too large. You’ll have to design new assets, but you can recycle the creative concepts that work well in your email campaigns.

How to Measure Lift from RCS

RCS rich messages cost 20–50% more per send than SMS. And while their higher conversion rates often justify the spend, their higher cost demands rigorous measurement. With that in mind, here is a test to run to determine whether or not spending on RCS is a wise move for your current campaign.

The RCS Testing Structure

Below are simple steps to setting up a test to see the value of RCS vs. SMS amongst your subscribers.

1. Segment by RCS eligibility first. Only RCS-capable devices should enter your testing pool.

2. Randomly split eligible users into an RCS group and an SMS control group.

3. Keep offer, timing and CTA the same across both RCS and SMS campaigns. The only variable amongst them should be visual formatting.

4. Track delivery status for both RCS-delivered recipients and SMS fallback recipients. Don't lump them together.

5. Run for at least one full purchase cycle, plus a buffer period to ensure that all subscribers interact with your content. If you typically run SMS campaigns on a 30-day cycle, run these tests for 45 days.

6. Report your numbers two ways. First, include everyone you tried to send RCS to (even those who got the SMS fallback), then again using only the people who actually received the RCS version. That second number is your real apples-to-apples channel comparison. Compare its success metrics to those of your SMS campaign

Success Metrics to Track for RCS vs. SMS Testing

• CTR (button clicks + link clicks)

• Conversion rate

• Revenue per message

• Cost per conversion

• Unsubscribe rate

• Carousel scroll depth (RCS-native metric)

RCS Compliance: What Changes, What Doesn't

The good news is if your SMS program is clean and operating properly, starting up your RCS program won’t be a hassle! Here’s a breakdown of what that will look like: 

• Telephone Consumer Protection Act (TCPA) laws still apply. Existing SMS consent covers RCS under its current interpretation. Still, we recommend you update your opt-in language to reference "SMS, MMS and/or RCS" for good measure.

• Mind the Federal Communication Commission's April 2025 rule. Honor opt-outs within 10 business days. STOP keywords work in RCS, too. Only one confirmation text is allowed within 5 minutes of an opt-out. Brush up on the full FCC guidance here and consult with your brand’s legal counsel to ensure all bases are covered.

• Google verification is required. To send branded RCS messages, your business must pass Google's verification process, which includes verifying your logo, display name, website, privacy policy and messaging intent.

• Carrier approval takes 8–16 weeks. Three major US carriers—AT&T, Verizon and T-Mobile—review applications individually. If you have a seasonal deadline, apply asap.

Start With One RCS Flow & Build On Its Success

RCS’s early data is hard to ignore. If you haven’t adopted the technology yet, have no fear! The easiest entry point is to test it out for your engaged shoppers. Send out cart abandonment messages or high-intent reengagement campaigns, with great product visuals and a one-tap purchase action. Then continue building RCS versions alongside your existing SMS flows, run the A/B test we discussed above and let the numbers tell you what to scale.

Personalized messaging, predictive content and RCS are only getting better and your subscribers already expect them. Your messaging program just needs to catch up.