RCS business messaging (RBM): how it works, pricing and iPhone support

RCS Business Messaging gets pitched as "SMS, but with carousels, buttons and a verified logo." That description is accurate. It also leaves out most of what you need to know before you build on it: who approves your sender, how messages are billed, and what happens to the large share of your list whose phones can't receive RCS on a given day.

This guide is for marketers and developers evaluating RBM. It explains how RBM differs from the RCS people use with friends, how the delivery path and approvals work, what the API options are, and how pricing is structured. It also covers where iPhone support stands and why the SMS fallback underneath RBM matters more than the rich features on top. We also say plainly where Ready fits and where it doesn't.

Consumer RCS vs RCS business messaging

RCS (Rich Communication Services) is the carrier messaging standard that replaced SMS for many phone-to-phone chats. When a friend's message shows typing indicators, read receipts and full-resolution photos in Google Messages, that's consumer RCS. For the basics, see what it means when a text says RCS.

RBM is the business layer on top of that standard, and it works very differently:

• Senders are "agents," not phone numbers. An RBM agent has a brand name, logo, color and description. The recipient sees a verified business profile, not a 10-digit number.
• Agents are approved, not just provisioned. You register the agent, a reviewer verifies the brand, and carriers approve the launch on their networks. Consumer RCS needs none of that.
• Messages can be structured. Rich cards, carousels, suggested replies and suggested actions (open a URL, dial a number, share a location) are part of the format. Consumer RCS chats are mostly free-form text and media.
• Delivery is conditional. Before sending, the platform checks whether the recipient's device and carrier can receive RBM. If they can't, the message doesn't go, and you need a fallback.

That last point shapes everything else in this article.

How an RBM message actually gets delivered

The path from your code to the recipient's phone looks like this:

1. You build an agent. Name, logo, banner image, contact details, privacy policy, and a description of the use case (for example, order updates or appointment reminders).
2. Brand verification. Someone confirms your business owns the brand the agent claims to represent.
3. Carrier launch approval. Each carrier you want to reach approves the agent separately. A US launch can be approved on one network and still pending on another.
4. Capability check at send time. Your provider asks whether this number can receive RBM right now. The answer depends on the device, the OS version, whether RCS is turned on, the carrier, and the country.
5. Send or fall back. If the number is capable, the rich message goes out. If not, you send an SMS (or MMS) version instead.

Steps 1 to 3 happen once per agent and can take a while, because several parties approve independently. Steps 4 and 5 happen on every send. Most of the engineering work sits in step 5: writing a plain-text version of every rich card that still makes sense with no buttons.

If you're comparing sender types side by side, our post on RCS benefits, limits and backing it up with SMS covers the fallback design in more depth.

Your API options for RBM

There are roughly three ways to reach RBM:

• Google's RBM platform directly. Google runs the main RBM infrastructure that carriers plug into. Going direct gives you the most control over agents and message formats. It also leaves you to handle fallback, carrier launches and SMS registration yourself.
• A CPaaS or messaging provider that has added RCS. Several large CPaaS vendors expose RBM through the same API you'd use for SMS, often with an automatic SMS fallback flag. This is usually the fastest path if you already send SMS through one of them.
• A marketing platform with RCS built into its campaign tool. You trade API flexibility for a visual card builder and campaign reporting.

When you compare providers, ask five questions:

• Who files the agent and carrier launches, and how do they report status per carrier?
• Is fallback automatic, and can you supply your own SMS text for each rich message?
• How are fallback SMS billed? At the normal SMS rate, on your registered 10DLC campaign?
• Are capability checks billed? If so, at what price?
• Where do replies land? Is a reply to an RCS message in the same thread as the SMS conversation with the same person?

The fourth question surprises people. Every one of these answers affects your real cost per conversation.

How RBM pricing works

RBM isn't billed per 160-character segment the way SMS is. Pricing varies by country, carrier and provider, so we won't quote figures. The structure usually follows a few models:

• Basic message: a text-only message up to a character limit, billed roughly like an SMS.
• Single (rich) message: one message with rich elements such as a card, image or buttons, billed as a unit.
• Conversation or session: once the recipient replies, a window opens (often 24 hours) in which back-and-forth messages are billed as one conversation rather than one by one.

Two practical consequences follow:

1. You can't compare RBM to SMS at the message level. A rich card that replaces a 3-segment SMS plus a link may cost more or less than those 3 segments. It depends on your provider's model and how many replies follow.
2. Your blended cost includes fallback. If a large share of your list falls back to SMS, a large share of your bill is SMS, and those texts are billed per segment.

Worked example: the SMS half of an RBM campaign

Assume a 10,000-contact appointment-reminder campaign. Purely for illustration, assume half the list can't receive RBM on send day, so 5,000 messages fall back to SMS. The fallback text is 175 characters with one emoji, which makes it 3 unicode segments (67 characters per multipart segment).

On Ready's Standard rate:

• Fallback segments: 5,000 × 3 = 15,000 segments
• Per-segment rate: 15,000 × $0.0075 = $113
• Carrier fee: 15,000 × $0.0045, itemized separately

Drop the emoji and trim the text to 160 characters, and it becomes 1 GSM-7 segment. That's 5,000 segments at the per-segment rate, plus the carrier fee. The plain-text fallback version is where you control cost, so write it as carefully as the rich card. Those figures exclude the optional compliance surcharge ($0.003 per segment each for scrubbing and landline validation, both off by default). For more segment math, see SMS API pricing explained.

iPhone support: what's real

Apple added RCS support to the iPhone with iOS 18. Before that, RBM simply didn't reach iPhones, which in the US meant a large share of any list fell back to SMS automatically.

The current picture is more nuanced than "RCS works on iPhone now":

• Consumer RCS between iPhone and Android works on supported carriers, with the recipient's RCS setting on.
• Business RCS to iPhones depends on carrier and region, and support has been rolling out unevenly rather than all at once. Whether a given iPhone can receive your agent's messages comes down to the capability check, not the OS version alone.
• Rich features may render differently. Test cards, carousels and suggested actions on real iPhones before you design a campaign around them.
• Older iOS versions and RCS-off devices still fall back. That group shrinks over time, but it doesn't disappear.

We wrote a longer take on what RCS on iPhone does and doesn't change for an SMS program in 2026. The short version: plan for RBM to cover part of your list, and plan for SMS to cover the rest for the foreseeable future.

Where Ready fits (and where it doesn't)

Ready doesn't send RCS Business Messaging today. If verified RBM agents with carousels are a hard requirement, choose a provider that offers RBM natively. Before you sign, ask the provider the five questions above.

What we do cover is the part of an RBM program every provider still relies on, plus a different route to a branded, rich-looking thread on iPhone.

The SMS layer RBM falls back to

Fallback SMS in the US goes over registered 10DLC routes. Unregistered traffic gets carrier-filtered, which makes a broken fallback worse than none. Ready handles brand and campaign registration in-app or through the API. Registration costs $25/mo and $2/mo per number, there's no setup fee, and most approvals take 2 to 7 days. Platforms registering customers programmatically can see how the 10DLC registration API works.

Once registered, a send is one request:

POST https://api.tryready.com/v1/messages
X-API-Key: <key>
Idempotency-Key: 6f1c2e8a-3b1d-4b7e-9a51-0c2f7d4e8b10

{"to": "+12125550199", "body": "Reminder: your appointment is tomorrow at 10 AM. Reply C to confirm.", "consent_attested": true}

STOP handling, quiet-hours holds and opt-out suppression apply automatically. Texts to opted-out numbers are refused up front and not charged. TCPA-litigator and DNC scrubbing is available if you switch it on. Compliance remains the sender's responsibility. These tools reduce risk; they don't remove it. Docs: docs.tryready.com/api/messages.

The blue line: iMessage instead of RCS for iPhones

If your reason for looking at RBM is "I want iPhone users to see my business name in a blue bubble," the blue line may get you there faster. It sends from your business as iMessage, with your name and photo, and needs no 10DLC registration. Replies, reactions and typing indicators land in the same inbox thread as SMS. Texts to Android phones go from your regular number at the regular rate if you already had a number; if the blue line came with its green number, your account's texts bill at 6 cents a segment once you register.

It costs $99 a month per line, plus 6 cents a segment for each text sent or received (reactions are free). Each line can start up to 50 new conversations a day, with up to 2 texts per person until they reply. It works best for one-to-one sales and support, not marketing campaigns, which send from regular numbers. Details are in the blue line guide, and the developer side is covered in our iMessage API for business post.

RBM, SMS and blue line compared

Should you adopt RBM now?

RBM is worth piloting if all of these are true:

• Your messages benefit from structure: order tracking with buttons, booking with suggested times, product carousels.
• You send enough volume that the agent and carrier approval work pays off.
• Your provider handles fallback automatically and lets you write the SMS version yourself.
• Your SMS registration is already approved, so fallback traffic isn't filtered.

It's reasonable to wait if most of your messages are short notifications or one-to-one conversations. A 1-segment SMS reminder doesn't gain much from a rich card, and a conversation with a lead gains more from a fast reply than from a carousel.

The practical takeaway

RBM is a real upgrade for structured, branded messages. But it's a layer on top of SMS, not a replacement. Every RBM send depends on a capability check, every failed check becomes an SMS, and every SMS in the US needs a registered 10DLC campaign behind it. Get the SMS layer registered and costed first. Then add RBM through a provider that supports it, or the blue line if iPhone branding is the goal.

If you want to set up that SMS layer, or try the blue line alongside it, you can create a Ready account. Your first 20 one-to-one texts are free. Use them to test before you register, since they end once a registration is paid for. Rates are on the pricing page.