The RCS Glossary.

Ten-digit long code: the US system for registered application-to-person SMS/MMS over standard local phone numbers. The same brand and campaign registration underpins RCS business messaging.

The latest generation of cellular network technology. RCS works over 5G like any internet connection (also 4G/LTE or Wi-Fi), since it is IP-based.

Comparing two or more message variants on a subset of an audience to see which performs better before a full send, used to optimize RCS engagement.

Application-to-Person messaging: messages sent programmatically by a business or application to a consumer (alerts, OTPs, marketing), as opposed to person-to-person texting.

Messaging that reminds customers of an incomplete purchase and invites them to complete it; RCS rich cards with the product image and a one-tap checkout button recover carts SMS and email often miss.

In RCS, the verified brand identity through which a business sends and receives messages. Also called an RBM agent or RCS agent.

The unique identifier for a verified RBM agent, included in API requests so messages are sent from the correct branded sender.

A message sent from an RBM agent to a user via the RCS Business Messaging API, addressed to the recipient's phone number.

Autonomous AI systems that can take actions on a user's or brand's behalf. RCS is considered an ideal channel for agentic AI because it is native, verified, rich, and two-way.

A messaging intermediary that connects businesses to carriers and the RCS ecosystem, handling registration, routing, and delivery. Many RCS providers operate as aggregators.

An automated conversational assistant that understands requests, offers suggested replies and actions, completes tasks, and hands off to a human when needed, increasingly delivered over RCS.

A list of approved test phone numbers permitted to receive messages from an RBM agent before it is fully launched, used for development and review.

Google's mobile operating system, on which RCS is delivered primarily through the Google Messages app.

The maker of iPhone and iMessage. Apple added RCS support in iOS 18.1 (2024) and default cross-platform end-to-end encryption in iOS 26.5 (2026).

Apple's business-chat channel within the Messages app on Apple devices, distinct from RCS. RCS handles cross-platform business messaging to Android and iPhone alike.

In registration terms, a business's verified legal identity, registered before it can run messaging campaigns. Distinct from a campaign (the specific use case).

A brand's primary color shown in its verified RCS sender presentation, part of the branded experience that distinguishes RCS from anonymous SMS.

The configured identity of an RBM agent, name, logo, hero image, color, description, and contact details, shown to recipients.

The process of registering a business's legal identity with The Campaign Registry (and Google/carriers) as a prerequisite for sending A2P messages, including RCS.

Additional verification of a registered brand's legitimacy, improving trust scores and messaging throughput; an enhanced vetting tier is also available at higher cost.

Sending a single message to many recipients at once (bulk messaging), as in a promotion or alert, as opposed to a one-to-one conversation.

Sending the same message to many recipients at once; synonymous with broadcast.

A registered, approved messaging use case under a brand (for example marketing, alerts, or support). Both a brand and a campaign are required to send A2P messages.

Registering a specific messaging use case under a brand with The Campaign Registry, including sample messages and opt-in details, before sending.

A query to the RCS backend, before sending, to confirm whether a destination number can receive RCS. If not, the message is sent as SMS/MMS instead.

An RCS message containing multiple rich cards (2-10) that the user swipes through horizontally; all cards share the same width and media height.

Whether a rich card is laid out vertically or horizontally. Vertical cards can be combined into a carousel.

A horizontally swipeable set of 2-10 rich cards in a single RCS message, ideal for showing multiple products, menu items, or properties.

A mobile network operator that provides cellular service and delivers messages to subscribers. US carriers supporting RCS include AT&T, Verizon, T-Mobile, and UScellular.

Spam and abuse filtering applied by carriers to A2P traffic; non-compliant or unregistered messaging can be throttled or blocked, making registration and consent essential.

Cross-Carrier Messaging Initiative: a joint venture announced by major US carriers in 2019 to deliver a unified RCS experience; it was later dissolved as the industry standardized on Google's platform.

California Consumer Privacy Act (with CPRA amendments): California privacy law granting disclosure, access, deletion, and opt-out rights that affect how messaging data is handled.

Google Messages' user-facing name for RCS. Turning on chat features enables RCS functionality such as read receipts, typing indicators, and high-resolution media.

An automated conversational agent delivered through an RCS agent using the MaaP framework, offering suggested replies and actions and handing off to a human or AI as needed.

A row of suggestion buttons (suggested replies or actions) shown below a message or card; up to 11 chips can appear below a rich card.

The percentage of message recipients who tap a link or button. RCS click-through commonly runs 15-30%, well above typical SMS.

An entry point, a link, button, ad, or QR code, that opens a messaging conversation with a business, a common way to start RCS conversations.

Joining multiple 160-character SMS segments into one longer text, each segment billed separately. RCS avoids this by supporting long messages natively.

A recipient's permission to receive messages. RCS requires explicit opt-in; marketing needs prior express written consent and transactional needs prior express consent.

The payload of an RBM message, containing text and/or a rich card plus any suggestions, sent to the recipient.

An ongoing two-way message thread between a user and an agent. Some providers also bill or measure by conversation session.

An identifier grouping the messages of a single conversation/session, used for threading and analytics.

AI that powers natural, automated conversations; combined with RCS it delivers branded, interactive, two-way experiences with human handoff.

Buying and selling through a chat conversation. RCS can host an entire purchase journey, discover, decide, buy, track, support, in one branded thread.

The percentage of recipients who complete a desired action (purchase, booking). RCS often lifts conversion versus SMS due to richer, one-tap experiences.

Communications Platform as a Service: a cloud platform offering messaging, voice, and related APIs. Providers like Twilio, Sinch, and Infobip are CPaaS vendors.

A suggested action that lets a user add an event to their calendar with one tap, including start/end time, title, and description.

A 2019 joint venture by major US carriers to deliver unified RCS; later dissolved as the industry consolidated on Google's RCS platform.

Call-to-action: the message or interface element inviting opt-in, which must disclose the brand, purpose, frequency, data-rate notice, and opt-out instructions.

The US wireless industry association whose Messaging Principles and Best Practices set consent, content, and opt-out standards for A2P messaging, including RCS, enforced by carriers.

The end-to-end path a customer takes across touchpoints. RCS can carry much of it, discovery, decision, purchase, support, in one thread.

A URL that opens a specific location inside an app rather than a website, often used in suggested actions to drive app actions.

The app a phone uses to send and receive texts. RCS works in the default app, Google Messages on Android, the Messages app on iPhone.

How reliably messages reach recipients, influenced by registration, trust scores, carrier relationships, and fallback handling.

The percentage of sent messages confirmed delivered to recipient devices, reported via delivery receipts.

A webhook event confirming a message reached the recipient's device.

A time range within which a scheduled message should be delivered, configurable via the API.

A suggested action that opens the phone dialer pre-filled with a number, letting the user call with one tap.

Do Not Call: registries and internal lists of contacts who must not be solicited; suppression of opted-out and DNC contacts is a compliance requirement.

A consent method where the user confirms a subscription (for example by replying YES) after signing up, proving the number belongs to them.

An automated sequence of messages sent over time based on triggers or schedules, used for onboarding, nurturing, or re-engagement.

Message content that changes per recipient using variables (name, order, balance), enabling personalization at scale.

The international standard format for phone numbers (country code plus number, e.g., +14155550123), used to address RCS and SMS messages.

End-to-end encryption: encryption readable only by sender and recipient. Personal RCS chats are E2EE (Universal Profile 3.0 via MLS); business RCS is encrypted in transit but not end-to-end.

A developer tool that simulates how RCS messages render and behave, used to build and test payloads without consuming live carrier quota.

See E2EE, encryption where only the communicating users can read the messages.

A measure of how much recipients interact with messages (opens, reads, clicks, replies). RCS typically drives higher engagement than SMS or email.

The standard of consent required for marketing messages: a clear, signed (including electronically) agreement to receive them.

Automatic switching to an alternate path or channel (such as SMS) when primary delivery fails, ensuring messages still reach recipients.

Automatic downgrade of an RCS message to SMS or MMS when the recipient can't receive RCS, so the message still arrives.

Federal Communications Commission: the US regulator that administers and enforces the TCPA, including consent and revocation rules for messaging.

RCS's ability to send files such as high-resolution images, video, and PDFs over the internet, well beyond MMS limits.

Customer data a business collects directly, with consent. It underpins compliant, personalized RCS messaging and reliable opt-in records.

Federal Trade Commission: the US consumer-protection regulator whose Telemarketing Sales Rule requires keeping consent records for at least five years.

The stages a prospect moves through toward conversion. RCS can compress the funnel by enabling discovery-to-purchase within one conversation.

General Data Protection Regulation: the EU privacy law governing personal-data processing, including consent and data-subject rights, relevant when messaging EU contacts.

Google's RCS platform and backend, powering RCS delivery for most carriers and the Google Messages app. See Jibe.

Google's messaging app, the primary RCS client on Android and the default on many devices.

A conversation among multiple participants. RCS group chats offer richer features than SMS/MMS group texts for participants who have RCS.

The default 7-bit SMS character encoding that limits a single SMS to 160 characters; longer texts are split into segments. RCS has no such cramped limit.

The GSM Association, the global mobile-operator body that owns and maintains the RCS Universal Profile standard.

A standard keyword that, when received, should return help or contact information to the user, as expected by CTIA and TCPA guidance.

The main banner image at the top of a verified agent's profile or a rich card, part of the branded RCS experience.

Full-quality images and video that RCS sends natively, without the heavy compression and size limits of MMS.

Apple's proprietary messaging service for Apple devices. Distinct from RCS, which Apple supports for cross-platform messaging with Android since iOS 18.1.

Messages shown to users inside a mobile app while they use it. Unlike RCS, it only reaches active in-app users.

A message or event sent from a user to an agent (mobile originated), delivered to the business's webhook.

The ability of RCS to work consistently across different carriers, devices, and apps, ensured by the GSMA Universal Profile.

Apple's mobile operating system. RCS is supported on iPhone since iOS 18.1 (2024); iOS 26.5 (2026) added default cross-platform end-to-end encryption.

Google's hosted RCS backend handling registration, capability discovery, routing, and delivery for most carriers and Google Messages.

The point at which a verified RBM agent is approved and goes live, able to message production users beyond the test allowlist.

Guiding prospects toward conversion with timely, relevant follow-ups. RCS supports this with branded, interactive messages and one-tap actions.

Transferring a conversation from an automated agent (chatbot/AI) to a human representative within the same RCS thread.

A brand's mark shown with its verified RCS sender, displayed alongside the name and verification badge.

A standard ten-digit phone number used for messaging; registered for A2P use under 10DLC.

Messaging as a Platform: the framework enabling chatbots and interactive services within RCS, allowing app-like conversational experiences in the inbox.

The fixed display height (short, medium, or tall) of media within a rich card; all cards in a carousel must use the same media height.

An RCS message whose primary content is a file such as an image, GIF, video, or PDF.

The standard disclosure that carrier message/data charges may apply, required in opt-in calls-to-action.

A unique identifier for an individual message, used to correlate sends with delivery, read, and interaction events.

A predefined, reusable message structure with placeholders for dynamic content, often pre-approved for a use case.

Messaging-Initiated Video Calls: the headline feature of Universal Profile 4.0 (2026), letting users start a video call from a text conversation; rollout depends on carriers and devices.

Messaging Layer Security: the protocol underpinning end-to-end encryption added in RCS Universal Profile 3.0 for personal chats.

Multimedia Messaging Service: the cellular standard for sending media in texts, limited by heavy compression and small file sizes. RCS supersedes it where supported, with MMS as a fallback.

Mobile Network Operator: a carrier that owns its network infrastructure and spectrum, such as AT&T, Verizon, or T-Mobile.

A message or event originating from the user's device and sent to the agent (inbound). Abbreviated MO.

A message sent to the user's device from the agent (outbound). Abbreviated MT.

An RBM agent use case combining transactional and promotional messaging in one agent, but excluding one-time passcodes (OTP).

Mobile Virtual Network Operator: a carrier that resells service on another operator's network. Many MVNOs (Cricket, Metro, Visible) support RCS via Google Messages.

The texting app built into a phone, where RCS operates without any separate download, Google Messages on Android, the Messages app on iPhone.

Querying attributes of a phone number, such as carrier, line type, or RCS capability, before sending, to route and personalize correctly.

An approach that coordinates messaging across multiple channels (RCS, SMS, WhatsApp, email, voice) so the customer experience is consistent regardless of channel.

The share of recipients who open a message. SMS open rates are around 98%; RCS read rates are also high, supporting strong engagement.

A suggested action that opens a web link, optionally in an app or webview, when the user taps it.

A recipient's explicit agreement to receive messages, required before a business may send RCS. Must be clear, affirmative, and recorded.

A word a user texts (for example JOIN or START) to subscribe to a program, a common consent-capture mechanism.

A recipient's withdrawal of consent. Senders must honor keywords like STOP, stop within 10 business days, and may send only one confirmation.

One-Time Passcode: a single-use code sent for authentication. RCS supports a dedicated OTP agent use case, with the verified sender reducing phishing risk.

Over-the-top messaging apps (WhatsApp, Messenger, Telegram) that run over the internet independent of carriers. RCS differs by living in the native inbox.

A message sent from an agent to a user (mobile terminated).

Person-to-Person messaging: ordinary texting between individuals, as opposed to A2P business messaging. Personal RCS chats are end-to-end encrypted.

Tailoring message content to the individual recipient (name, history, preferences), which lifts RCS engagement and conversion.

Fraudulent messages impersonating a trusted party to steal information. RCS verified senders make brand impersonation far harder than over SMS.

The mobile number that addresses RCS and SMS messages, formatted in E.164 for APIs.

The data returned to a business when a user taps a suggested reply or action; see postbackData.

A developer-defined string attached to a suggested reply or action, returned to the webhook when the user taps it, so the tap maps to intent without parsing text.

The consent standard for non-marketing (transactional/informational) messages: clear permission to be contacted, though not necessarily in writing.

The handling of personal data in messaging, governed by laws such as TCPA, CCPA/CPRA, and GDPR, plus a linked privacy policy at opt-in.

An RBM agent use case for marketing messages (offers, campaigns), which require prior express written consent.

The carrier-side process of enabling RCS for a subscriber or sender, including registration on the RCS backend.

An alert delivered through an installed app. Unlike RCS, it requires the customer to have downloaded the app and enabled notifications.

Subscribing by scanning a QR code that opens a pre-filled opt-in message or sign-up, popular for in-store and print enrollment.

An informal name for a suggested reply, a tappable button that sends a predefined response.

Time windows (often overnight) during which marketing messages should not be sent, per regulations and best practice.

Limits on how many API requests or messages can be sent in a time window, to protect platform stability; high-volume senders manage throughput accordingly.

RCS Business Messaging: the framework and ecosystem for verified brands to send rich, interactive RCS messages to customers, with SMS fallback.

A brand's verified sender identity in RCS Business Messaging, carrying its name, logo, and verification, with an assigned use case and an agent ID.

Rich Communication Services: the GSMA's open standard that upgrades SMS/MMS into a rich, interactive, internet-based messaging experience in the native inbox, with SMS fallback.

Synonym for RBM agent, a business's verified RCS sender identity with a use case and agent ID.

The REST interface for sending RCS messages from a verified agent and receiving interactions via webhooks, after a capability check, addressed by agent ID.

The application-to-person side of RCS, managed by Google, that lets verified brands send rich, branded, interactive messages with SMS fallback. Abbreviated RBM.

Sending and receiving messages over the RCS protocol, richer for consumers and verified, interactive, and branded for businesses.

How RCS messages are directed: a capability check determines RCS versus SMS/MMS, then RCS-capable messages travel over IP through the backend to the device.

Messaging lapsed or inactive customers to win them back; RCS reaches them in the inbox even if they abandoned a brand's app.

An emoji response applied to a message (e.g., a thumbs-up), supported in RCS like modern chat apps.

The percentage of delivered messages that recipients read, reported via read receipts; RCS read rates are typically high.

A webhook event (or chat indicator) confirming the recipient opened/read a message. Users can disable read receipts in personal chats.

Enrolling a brand, campaign, and sender with the registry, Google, and carriers so a business can send compliant RCS.

A web API style using standard HTTPS requests and JSON. The RCS API is RESTful, so any language that makes HTTPS calls can use it.

A recipient's withdrawal of consent by any reasonable means. Under FCC rules (effective April 2025) senders must honor it within 10 business days.

A single RCS message combining optional media, a title, a description, and tap-to-act buttons (at least one of media/title/description required), with up to four suggestions.

The full name of RCS: the GSMA standard modernizing SMS/MMS with rich, interactive, branded messaging in the native app.

Text styling (bold, italics, strikethrough) added to RCS in Universal Profile 4.0 (2026); availability depends on carrier and device rollout.

Using a mobile network outside the home network's coverage. RCS works while roaming with a data connection and supporting networks; otherwise it falls back to SMS.

Return on investment: incremental revenue minus all-in cost, divided by cost. RCS ROI is often strong because higher engagement lowers cost per outcome.

A non-production environment for building and testing RCS integrations without sending to live users.

A message queued to send at a future time or within a delivery window, configured via the API or app.

Structured data (Schema.org) added to web pages so search and AI systems understand content.

A read indicator/event signaling the recipient viewed the message; equivalent to a read receipt.

Dividing an audience into groups by attributes or behavior to send more relevant, personalized messages.

The identity a message appears to come from. In RCS this is a verified agent (brand name, logo, badge), unlike easily-spoofed SMS sender IDs.

A bounded period of two-way conversation between a user and agent; some pricing and analytics are session-based.

Sex, Hate, Alcohol, Firearms, and Tobacco: content categories restricted or prohibited in A2P messaging; carriers can penalize senders for prohibited content.

A suggested action that prompts the user to share their current location with the agent in one tap.

A 5-6 digit number used for high-volume A2P messaging, leased and approved through carriers; an alternative addressing option to 10DLC long codes.

SMS phishing: fraudulent text messages designed to steal information. RCS verified senders help recipients distinguish genuine brand messages.

Short Message Peer-to-Peer: a protocol for high-volume SMS exchange between applications and carriers, offered by some providers alongside REST APIs.

Short Message Service: the original 160-character plain-text cellular messaging standard. Universal and reliable, it is the fallback layer beneath RCS.

Automatically delivering a message as SMS (or MMS) when the recipient cannot receive RCS, preserving reach.

A single 160-character (GSM-7) unit of an SMS message; long messages are split into multiple billed segments. RCS sends long messages without segmentation.

Unsolicited bulk messaging. RCS reduces it through enforced opt-in, registration, and verified senders, with carriers filtering abusive A2P traffic.

Faking a sender's identity. SMS sender IDs are easily spoofed; RCS resists this through verified, vetted senders shown with a badge.

A single rich card sent on its own (not in a carousel), combining media, title, description, and suggestions.

A universal opt-out keyword; receiving it (or QUIT, END, CANCEL, UNSUBSCRIBE, OPT OUT, REVOKE) requires the sender to stop messaging.

Video that plays within a rich card, added to business messaging in Universal Profile 4.0 (2026); rollout depends on carriers and devices.

A webhook event signaling a user opted in to an agent, used for consent management.

A tappable button that triggers a device action, open URL, dial, view/share location, or create a calendar event, with display text and postbackData.

A tappable button that sends a predefined response in one tap (up to ~25 characters), returning postbackData to the webhook, the cleanest way to capture intent.

An umbrella term for suggested replies and suggested actions, the tappable buttons that make RCS interactive.

A single app combining many services (chat, commerce, payments, services). RCS is increasingly described as evolving toward a super-app surface in the inbox.

Telephone Consumer Protection Act: the US federal law governing automated calls and texts, including consent and opt-out rules, enforced by the FCC and via private lawsuits.

An FTC rule governing telemarketing that, among other things, requires keeping consent records for at least five years.

A phone on the agent's allowlist used to preview and test messages before launch.

TCR: the US registry managing brand and campaign registration for A2P messaging, charging brand, vetting, and campaign fees that providers pass through.

The rate at which messages can be sent, often expressed as transactions per second; influenced by trust scores and provider limits.

Scheduling messages to arrive at an appropriate local time for each recipient, improving engagement and compliance with quiet hours.

Transport Layer Security: the encryption protecting RCS messages in transit between user, provider, and backend. Business RCS uses TLS but is not end-to-end encrypted.

A2P messaging over toll-free numbers, a verified alternative to short codes and 10DLC long codes for business texting.

Transactions Per Second: the throughput limit governing how many messages an account can send per second.

A URL with parameters that records clicks, letting senders measure engagement from message buttons and links.

An RBM agent use case for non-marketing notifications (confirmations, updates, alerts), which require prior express consent.

A general term for the verification checkmark and branded identity that signal a genuine, vetted RCS business sender.

A rating of a registered brand's or campaign's legitimacy that influences messaging throughput and deliverability; better vetting raises it.

Verifying identity with a second factor, commonly a one-time passcode. RCS can deliver these via a verified OTP agent.

Conversational messaging where recipients can reply and interact, enabling support, surveys, and commerce, native to RCS.

The animation showing that the other party is composing a message, supported in RCS but not SMS.

The GSMA specification defining RCS features and technical enablers so implementations interoperate across carriers and devices.

The RCS Universal Profile version (March 2025) that introduced end-to-end encryption for personal chats via the MLS protocol.

The RCS Universal Profile version finalized March 2026, adding Messaging-Initiated Video Calls, rich-text formatting, and streaming video in rich cards; rollout depends on carriers and devices.

A webhook event signaling a user opted out of an agent, used to suppress further messaging for consent compliance.

Measuring taps on links within messages, often via tracking links, to gauge engagement and conversion.

A US carrier that supports RCS, alongside the three major operators; it also applies per-message A2P carrier surcharges.

The defined purpose of an RBM agent or campaign, OTP, transactional, promotional, or multi-use, governing what it may send.

How long a message remains valid for delivery before it expires if undeliverable.

Placeholders in a message or template (such as name or order number) replaced with recipient-specific values at send time.

The checkmark shown with a verified RCS sender, signaling that Google and carriers have vetted the brand, RCS's anti-spoofing cue.

A business RCS identity vetted by Google and carriers, displayed with the brand's name, logo, and verification badge, the core anti-spoofing feature of RCS.

Google's earlier feature that displayed brand verification on SMS, a precursor to the verified senders now native to RCS Business Messaging.

The review process that validates a brand's legitimacy for messaging, affecting trust scores and throughput; enhanced vetting is available at higher cost.

Starting a video call from a conversation, introduced to RCS as Messaging-Initiated Video Calls in Universal Profile 4.0 (2026).

A suggested action that opens a map at a specified location (latitude/longitude with a label) when tapped.

An HTTPS endpoint where the RCS platform sends real-time events, inbound messages, suggestion taps, delivery and read receipts, typing, and opt-in/out.

A single notification delivered to a webhook, such as delivered, read, inbound message, suggestion response, typing, failure/fallback, or subscribe/unsubscribe.

Meta's business-messaging product on the WhatsApp app. It offers rich, two-way messaging but requires the app, unlike RCS which lives in the native inbox.