RCS on iOS: known limitations and what to expect

RCS is a carrier-backed messaging standard that has matured primarily on Android. Apple has only recently added support for RCS on iOS, and that implementation is still evolving.

As a result, some RCS features may behave differently or inconsistently on iOS compared to Android. These limitations are dictated by Apple’s OS-level RCS implementation and are outside the control of Klaviyo, Google, carriers, or Klaviyo’s RCS partners.

This article explains:

• Why RCS behaves differently on iOS
• The known iOS-specific issues we are aware of
• What to do if you encounter an issue
• What to expect during Apple’s issue resolution

Why RCS behaves differently on iOS

RCS messages are rendered and handled entirely by the native Messages app on each operating system and Apple’s RCS implementation does not yet offer full parity with Android.

As a result, Klaviyo cannot control or override:

• Message layout and rendering
• Button placement and behavior
• Media rendering
• Thread preview text and caching behavior

These behaviors are dictated by Google & Apple’s OS-level RCS support and may vary by:

• OS version
• Device model
• Carrier configuration

Known RCS issues on iOS

Below is a list of known issues that have been observed on some iOS devices. This list will change over time as Apple releases fixes, but some users on older OS versions may still experience these behaviors.

Agent (sender ID)

• The agent ID may be displayed instead of the agent name
• Banners do not display on the agent information page

Rich cards

• On Android, image height can be set explicitly. On iOS, images are automatically resized based on text size and length, which can cause images to appear squashed.
• Button color appears gray and lacks visual prominence.
• Button labels may be cached incorrectly and display the wrong text in message threads.
• When multiple buttons are present, they are included in a dropdown and the label defaults to “options”.
• Quick action URL links appear inside card buttons instead of in a separate bubble below the card.
• Quick reply buttons appear in a separate bubble below the card where quick actions are expected.
• If a card has no title, the preview text will display as “one message”.

Media and content

• GIFs render as static images rather than animated

URLs and previews

• URLs placed at the end of a message with no trailing text will be sent as a separate bubble with “tap to preview”
  • Workaround: add a period or other character after the link.

Important notes about these issues

• These issues do not occur on all devices or iOS versions
• Some issues may already be fixed in the latest iOS releases
• Users on older OS versions may still experience problems

Our goal is to make brands aware of all known limitations so they can design RCS experiences defensively.

Test your message before sending

Before scheduling a campaign or activating a flow, send a test to both an iOS and an Android device to check how your message appears and behaves. Use devices that can receive RCS, and make sure you have an active RCS agent in their countries.

1. In the RCS message editor, click Preview.
2. Enter the phone numbers for your test devices, then click Send test.
3. On each device, review the message layout, images, button labels, and link behavior.

If a device receives the SMS or MMS fallback, it has not tested the RCS version. Behavior can still vary across iOS versions, device models, and carrier configurations.

What to do if you encounter an issue

If you encounter any of the issues listed above, or discover a new iOS-specific RCS issue:

1. Submit feedback to Apple

Report iOS-specific RCS rendering issues to Apple using its Messages feedback form.

1. Go to the Apple feedback page for Messages.
2. Describe the RCS behavior you observed, what you expected, the iOS version, the device model, and the steps to reproduce the issue.
3. Submit the form and keep a copy of your report.

Apple reads feedback but may not respond to each submission.

2. Share the issue with Klaviyo Support

Share the same issue details with Klaviyo Support, along with any screenshots that show the problem. If you have an Apple Feedback ID, include it.

This allows us to:

• Track the issue
• Aggregate feedback across customers
• Actively raise and escalate the issue with Apple where possible

Issue resolution

Klaviyo does not have visibility into Apple’s RCS roadmap, timelines, or prioritization.

We cannot:

• Commit to fix dates
• Influence release schedules
• Patch Apple’s OS-level RCS implementation

Detailed feedback helps Apple understand how many people are affected by an issue and how to reproduce it. Sharing Apple Feedback IDs with Klaviyo Support helps us advocate for our customers with Apple.

Summary

• RCS on iOS is still maturing and does not yet match Android behavior
• All rendering and interaction issues are controlled by Apple
• Known issues may vary by OS version and device
• Submit feedback to Apple and share the issue details with Klaviyo Support, including an Apple Feedback ID if you have one
• Detailed feedback helps Apple understand an issue’s impact

We will continue to monitor, document, and communicate any new iOS-specific RCS issues as we become aware of them.