Getting started with RCS

Once an RCS agent is activated in your Klaviyo account, RCS becomes the default message format for all text messages in the countries where you have an active agent.

This means that any text messages sent via campaigns, flows, or conversations will automatically be delivered over RCS to RCS-capable devices. Recipients who are not RCS-capable will instead receive the SMS fallback.

Why we make RCS the default

You can send text-only messages over RCS without incurring additional costs compared with SMS in most countries, and in some scenarios RCS can deliver cost savings. For pricing, please contact our Sales team.

Because RCS offers a richer, more modern messaging standard, it provides clear advantages over SMS even for simple text-only use cases:

• Verified branded sender ID (SID): Messages are sent from your verified brand name, building trust and improving recognition with customers.
• Modern data networks: RCS is delivered over IP-based networks, which improves deliverability and throughput compared with legacy SMS channels.
• Open receipts: You gain visibility into when messages are opened, something not possible with SMS.
• Single-threaded communication: All customer conversations are maintained in one branded thread, instead of fragmented across multiple threads. Additionally, if you mix RCS and SMS, any SMS messages delivered by unbranded numeric senders may be mistaken for spam, since the consumer will view the RCS agent as the legitimate source.

These benefits apply automatically to all text messages once your RCS agent is activated.

SMS fallback

Because not all carriers and devices support RCS, every RCS message includes an SMS fallback. This ensures:

• RCS-capable recipients get the RCS version
• Everyone else still receives your message as an SMS

You can customise your SMS fallback separately to optimize for SMS and reduce costs (e.g. by removing special characters or media.

Compliance and consent

All SMS regulations also apply to RCS since both channels are delivered via carrier-managed networks and appear in the same inbox on a mobile device.

This means:

• SMS consent applies to RCS, and vice versa. You can send RCS messages to your existing SMS list without re-obtaining consent.
• Opt-outs apply across both channels. If a recipient opts out of RCS, you cannot revert to sending them SMS. They have opted out of all text messaging.

Always follow local SMS compliance requirements (e.g. opt-in rules, prohibited content etc.) when sending RCS.

Pausing RCS

If you want to stop sending RCS messages, you can deactivate your RCS agent. Once deactivated, all text messages will revert back to SMS delivery.

• In the future, you’ll be able to do this directly in Klaviyo settings.
• For now, if you want to pause RCS in a specific country, please reach out to Klaviyo Support.

Best practices when getting started

• Review existing flows: If you already had SMS messages in flows before RCS was enabled, your SMS content will have been copied into the RCS version. Review and update these to take advantage of RCS features, and edit the SMS fallback separately if needed.
• Avoid contact cards: Contact cards are not supported in RCS (you cannot save an RCS agent as a contact). Review any existing messages that include contact cards and update the RCS version to remove them.
• Monitor performance: Use open receipts to track engagement, but note that read receipts are off by default on iOS and on by default on Android. This means read receipts are not a fully accurate measure of who has viewed your message, since most iOS devices will not return read data.
• Segment if needed: If you prefer to send only to RCS-capable recipients, use the RCS capability property in segmentation.
• Check billing forecasts: While text-only RCS usually matches SMS pricing, adding rich content (images, buttons, carousels) will increase credit usage. Always review your billing forecast before sending.

FAQs

Do I need to enable RCS manually in each campaign or flow?

No. Once your RCS agent is activated, RCS automatically becomes the default text message format. All text message campaigns, flows, and conversations will use RCS for RCS-capable recipients.

What happens if a recipient’s carrier or device doesn’t support RCS?

They will automatically receive the SMS fallback. You don’t need to take any action to ensure message delivery.

Can I send only RCS or only SMS messages?

Yes. While RCS will always deliver to RCS-capable devices by default, you can choose to target only RCS-capable or only SMS-capable recipients using the RCS capability property:

• Segmentation: Build an audience of either RCS-capable or non-RCS-capable contacts and send your campaign to just that group.
• Conditional splits in flows: Use the RCS capability property to create a conditional split in a flow.

This lets you run RCS-only or SMS-only campaigns and flows when you want to separate your strategy for each audience.

Does RCS always cost the same as SMS?

For basic text-only RCS messages, RCS generally costs the same as SMS in most countries and in some scenarios RCS can deliver cost savings vs. SMS.

For rich messages (e.g. cards), costs may be higher

For pricing details, please contact our Sales team.

Can I stop using RCS after it’s been enabled?

Yes. You can deactivate your RCS agent and all messages will revert back to SMS. For now, this requires contacting Klaviyo Support, but in future you’ll be able to manage this in settings.

Are contact cards supported in RCS?

No. Contact cards cannot be sent via RCS since you cannot save an RCS agent as a contact. If any of your existing messages include them, update the RCS version to remove mention of the contact card or use a conditional split to avoid sending the message to RCS-capable devices.

Do I need separate consent for RCS?

No. SMS and RCS share the same consent requirements. If you have already obtained SMS consent, you can send RCS to that profile. However, if someone opts out of RCS, that opt-out applies to all text messaging, and you cannot switch back to sending them SMS.