RCS Subscribe and Unsubscribe

The Subscribe and Unsubscribe feature allows end users to control whether they want to receive non-essential messages (such as promotions and marketing content) from your RCS agent. This guide explains how the feature works and how to implement it in your application.

End users can manage their subscription preferences directly within the Google Messages app:

• Unsubscribe option is always available in the chat menu
• For promotional and multi-use agents, the unsubscribe option also appears directly in the chat after a certain number of unread messages
• Subscribe option becomes available once a user has unsubscribed, allowing them to opt back in

Synthetic Text Messages

In addition to the webhook events, you will receive an inbound text message containing a localized keyword. The keyword is automatically determined based on the country code of the end user's phone number.

Subscription Keywords by Country

The following table shows the localized opt-in and opt-out keywords for each supported country:

Example Flows

Scenario 1: User in Mexico Unsubscribes

A user with phone number +52 555 1234 taps "Unsubscribe" in Google Messages:

• User taps Unsubscribe in Google Messages
• You receive an inbound message with the text: BAJA
• Your system processes the opt-out request and updates the user's subscription status

Scenario 2: User in France Resubscribes

A user with phone number +33 6 12 34 56 78 taps "Subscribe" in Google Messages:

• User taps Subscribe in Google Messages
• You receive an inbound message with the text: Démarrer
• Your system processes the opt-in request and updates the user's subscription status

Important Implementation Notes

Processing Subscription Messages

Message Detection

Your system should monitor inbound messages for the subscription keywords listed in the table above. When you receive a message containing one of these keywords:

• Match the keyword: Identify whether it's an opt-out or opt-in keyword
• Update subscription status: Immediately update the user's subscription preference in your system
• Handle the request: Apply the appropriate business rules (see Compliance Requirements below)

Compliance Requirements

When a User Unsubscribes

You must comply with the following business rules:

• Acknowledge the request: If you cannot process the unsubscription immediately within the message thread, send an acknowledgment message with a direct link to your website or app where users can manage subscription preferences
• Stop non-essential messages: After unsubscription, you are prohibited from sending non-essential messages (promotions, marketing, etc.)
• Essential messages are still allowed, including:
  • Authentication messages (OTPs, verification codes)
  • Notifications about specific services the user has requested and consented to
  • Confirmation of the unsubscribe request with information to manage communication preferences

When a User Subscribes

Your system should treat a user as resubscribed only when you receive one of the localized opt-in keywords listed in the table above (for example, START, ALTA, Démarrer, or começar). These keywords are sent when the user explicitly taps the Subscribe button in Google Messages.

After receiving and processing a valid opt-in keyword, you may resume sending all message types to that user, including non-essential content such as promotions and marketing, in line with Google RCS policies and your own terms.

To resume promotional or marketing messaging, the user must explicitly resubscribe using the opt-in keywords.

Conversation Status

• After unsubscription, the conversation remains in the user's inbox unless reported as spam
• Google monitors message patterns after unsubscription to identify policy and business rule violations

Best Practices

• Monitor for subscription keywords: Build your subscription management logic to detect and process the localized opt-in and opt-out keywords listed in this guide.
• Case-sensitive matching: Ensure your keyword detection matches the exact case shown in the keyword mapping table (e.g., "BAJA" not "baja").
• Store subscription state: Maintain a persistent record of each user's subscription status based on their phone number.
• Respect user preferences: Strictly adhere to the prohibition on non-essential messages after unsubscription.
• Test across regions: Ensure your system correctly handles the different localized keywords for your target markets.
• Handle edge cases: Consider how your system will handle partial matches or similar words to avoid false positives.