What is RCS?
Rich Communication Services (RCS) for business is a messaging protocol that enhances traditional SMS with verified brand identity. With AWS End User Messaging, you can send RCS text messages to recipients in the United States and Canada, with automatic SMS fallback for devices or carriers that don't support RCS.
RCS messages appear in the same messaging app that recipients use for SMS, but include
your verified brand name, logo, and colors. This makes RCS an in-place upgrade rather
than a new channel to adopt. Customers using the SendTextMessage API can
start using RCS with minimal to no code changes, and end users don't change their
messaging flow. Verified identities inspire trust, encourage conversations, enhance
existing messaging use cases, and open the door for new use cases like conversational
experiences.
Important
Google is part of the message delivery chain for delivering your RCS
messages. Accordingly, your use of the RCS messaging channel in AWS End User Messaging is
also subject to the
Google
RCS for Business Terms of Service
Topics
Key benefits of RCS
RCS messaging through AWS End User Messaging provides the following benefits over traditional SMS:
- Verified brand identity
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RCS messages display your brand logo, name, and colors alongside a verified badge on Android devices. Recipients can confirm that the message is from your organization, which reduces the risk of phishing and improves engagement.
- Delivery receipts (DLRs)
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RCS provides device-level delivery receipts that confirm when a message has been delivered to the recipient's device. Unlike SMS, where delivery confirmation comes from the carrier network, RCS DLRs report directly from the device, giving you stronger assurance of actual delivery. This is also tied to billing. With RCS, you only pay for messages that are confirmed delivered to the device, whereas SMS charges are incurred when the message is accepted by the carrier.
- Improved messaging performance
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Messages delivered via RCS tend to achieve better business results compared to SMS because verified brand identity increases recipient trust and engagement. While RCS is not yet as universally available as SMS, the subset of messages delivered via RCS typically sees higher open rates and conversions. For recipients whose devices or carriers do not support RCS, automatic SMS fallback ensures your messages still reach them.
- Automatic SMS fallback
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When you send messages through a phone pool that contains both an AWS RCS Agent and SMS phone numbers, AWS End User Messaging automatically falls back to SMS if RCS delivery is not possible. This ensures your messages reach recipients regardless of their device or carrier support for RCS.
How RCS differs from SMS
The following table compares RCS and SMS messaging capabilities in AWS End User Messaging.
| Feature | RCS | SMS |
|---|---|---|
| Brand identity | Verified brand name, logo, colors, and badge | Phone number or sender ID only |
| Delivery confirmation | Device-level delivery receipts: the recipient's device reports back directly, confirming actual delivery. You are only billed for confirmed deliveries. | Carrier-level confirmation: the carrier network acknowledges receipt, but this does not guarantee the message reached the device. You are billed when the carrier accepts the message. |
| Message content | Text messages | Text messages, MMS for media |
| Device support | Android devices with RCS enabled, iPhone with iOS 18 or later | All mobile devices |
| Supported countries | United States and Canada | Over 200 countries and regions |
Why SMS fallback is essential
Not all mobile devices and carriers support RCS. For example, older Android devices, some carriers, and iPhones running iOS versions earlier than 18 cannot receive RCS messages. For most use cases, you need a reliable way to reach all recipients regardless of their device or carrier.
Phone pools solve this problem. A pool is a container of messaging identities that provides an abstraction layer between your API requests and your origination identities. Instead of putting SMS fallback number selection logic in your application, you add RCS agents and phone numbers to a pool and AWS End User Messaging handles the rest. This gives you three advantages:
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Easy RCS-to-SMS fallback without worrying about which numbers work in which country. Add your identities to a pool and the service selects the right one automatically.
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Number and agent selection logic stays out of your application code and in easy-to-manage configuration. You can add or remove identities without changing your sending integration.
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While simple to set up, pools also allow complete control over how you use numbers and RCS agents together, including per-use-case pools for compliance-safe routing.
To use SMS fallback, create a phone pool that contains both your AWS RCS Agent and one or more SMS phone numbers. When you send a message using the pool, AWS End User Messaging attempts RCS delivery first and automatically falls back to SMS if needed. We recommend pool-based sending for all messaging use cases, not just RCS, because it provides flexibility to add or change origination identities without modifying your application code.
Note
If you send a message directly to an AWS RCS Agent (without using a pool), SMS fallback is not available. Use direct sending only when you require RCS-or-nothing delivery or when you manage fallback logic outside of AWS End User Messaging.
Supported RCS capabilities
The initial launch of RCS in AWS End User Messaging supports text-only messaging in the United
States and Canada. You can send and receive plain text RCS messages using the same
SendTextMessage API that you use for SMS.
RCS in AWS End User Messaging currently supports the following:
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Sending and receiving text messages through RCS
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Verified brand identity (logo, name, colors, and verified badge)
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Delivery receipts (DLRs)
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Automatic SMS fallback with pool-based sending
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Two-way messaging (receiving inbound RCS text messages)
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Keyword management for auto-responses
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CloudWatch metrics for RCS message monitoring
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Country launches in the United States and Canada
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RCS testing agents for testing without carrier approval
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Phone mockups in the console to preview how your brand appears on devices
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A single AWS RCS Agent resource that manages country-specific registrations for both the US and Canada
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Shared registration details across countries, with per-country customization
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All AWS End User Messaging capabilities including configuration sets, phone pools, opt-out lists, and keywords
Note
RCS testing agents are typically created and approved within minutes, compared to SMS phone number registrations which can take days or weeks. This allows you to start testing RCS messaging quickly.
Understanding the two-level identity model
RCS in AWS End User Messaging uses a two-level identity model: the AWS RCS Agent (a container you create and manage) and one or more RCS for Business IDs (per-country agent identities created during registration). For complete details on how these identities relate, including lifecycle states and the comparison table, see Understanding the two-level identity model.
