RCS Business Messaging: Run RCS and WhatsApp in One Inbox

TL;DR: Mid-market B2C businesses answer every RCS reply in the same inbox as WhatsApp, Messenger and Instagram with respond.io

Mid-market B2C businesses add respond.io’s Twilio RCS Channel when RCS campaign replies sit in the Twilio console or a separate texting tool, where no agent owns them and one customer can show up as two records.

Respond.io is a customer conversation platform that puts RCS conversations in the same Inbox as WhatsApp, Messenger and Instagram. Workflows assign each new conversation an owner, and merge suggestions flag profiles that share a phone number so an agent can merge them into one Contact record. At launch, RCS covers text, images, video, audio and PDF in the Inbox, plus broadcasts and Workflows.

Each RCS conversation sits on a respond.io Contact record that can connect to the CRM you already use, such as HubSpot through its native integration.

Not a fit if RCS will be your only messaging channel and one person answers every reply, or if your campaigns depend on rich cards, carousels or SMS fallback managed in the same platform.

Mid-market B2C businesses adding RCS business messaging need its replies answered in the inbox their agents already use for WhatsApp, Messenger and Instagram, with an owner for every reply and one record for every customer.

RCS (Rich Communication Services) is the next generation of SMS. It’s built into the default messaging app on supported phones and adds a verified sender profile, images, video and files. Respond.io supports it through Twilio, so US B2C teams can answer RCS from the same inbox as their other channels.

Where RCS replies go unanswered, and why B2C teams move them into one inbox

Respond.io connects a Twilio RCS Sender as one more Channel, so RCS conversations arrive in the same Inbox, run through the same Workflows and sit on the same Contact records as WhatsApp, Messenger and Instagram. Respond.io is a customer conversation platform that includes the RCS channel through Twilio, a shared Inbox, Workflows and Reports.

RCS replies go unanswered when they land in the Twilio console or a texting app nobody watches. Customers who asked a question wait, some never get an answer, and a customer who also messages on WhatsApp shows up as two unlinked records, so two agents can give two different answers. Each of those costs leads from customers who already answered your campaign.

RCS replies land where agents already work

You connect your Twilio RCS Sender with your Account SID and Auth Token, and respond.io sets up the webhook for it.

From then on, RCS conversations appear in the Inbox next to WhatsApp, Messenger and Instagram, so agents answer them from the screen they already have open. RCS has no messaging window, so agents can reply or follow up at any time, with no 24-hour window to work around.

Each new RCS conversation gets an owner

Workflows can start when a customer opens a conversation and run the Assign To Step. That Step assigns the Contact to a specific agent, to someone in a team or to anyone in the workspace.

For teams and workspaces, it can share new Contacts out by round robin or give each one to the agent with the fewest open Contacts, and it can limit assignment to agents who are online. An RCS reply no longer depends on who notices it first. For more on rules and routing strategies, read our guide to automatic conversation assignment.

One customer stays one Contact record

A customer who messages you on RCS and on WhatsApp can start out as two Contact profiles, one per channel. Respond.io's merge suggestions list profiles that share a phone number or email address, so when the RCS and WhatsApp profiles carry the same number, the agent sees the suggested match in the Contact details.

Once the agent confirms the two are the same person, merging them leaves one complete Contact record, and the next agent who opens the conversation works from that single profile. An agent confirms each merge before it happens, and if a merge goes wrong, Owners and Managers can unmerge it from the Contacts Module.

How RCS business messaging works alongside WhatsApp, SMS, Messenger and Instagram

RCS business messaging reaches customers in the default messaging app on their phone, so it suits customers who prefer to text a business. Mid-market B2C teams add it alongside their other channels, with each channel covering a different group of customers:

RCS: Customers whose phone, carrier and country support it. They get a verified sender profile, images, video and files without downloading another app.
SMS: Customers RCS can’t reach yet. Fallback from RCS to SMS is set up in Twilio.
WhatsApp: Customers who already message businesses on WhatsApp and expect to reach you there.
Messenger and Instagram: Customers who find you on Facebook or Instagram and start a chat from your page, profile or ads.

On respond.io, every one of these channels shares the same Inbox and Contact records. A customer who texts on RCS and later messages on WhatsApp reaches one history once an agent merges the two profiles. A Multichannel Widget on your website lets visitors pick RCS, WhatsApp or Messenger, so customers whose phones don’t support RCS still have a way to start a chat.

Twilio console, texting tool or one inbox: where RCS replies should be answered

RCS replies should be answered in the same inbox as your other channels. Forwarding replies, running a texting tool beside the inbox and reporting from two tools all move RCS replies somewhere visible, but none of them gives a reply an owner or links it to the customer’s record, and respond.io does both.

Forwarding Twilio replies to email or a group chat

Everyone on the team can see the reply, but no one is assigned to it, so the first response depends on who notices and who assumes someone else already answered. In respond.io, the Assign To Step gives the conversation an owner when it opens, so the question of who replies is settled before anyone reads the message.

Running a texting tool beside the main inbox

The texting tool and the inbox each keep their own contact list. An agent answering on RCS can’t see that the same customer asked about an order on WhatsApp yesterday, because that conversation lives in a different product with no way to connect the two. In respond.io, both profiles sit in the same workspace, so merge suggestions can flag the shared phone number, something a separate texting tool can’t do for contacts it doesn’t hold.

Reporting from two tools

When RCS sits in a separate tool, a manager can’t see in one place whether RCS replies get answered as quickly as WhatsApp replies. Respond.io lets you filter Reports by the RCS Channel. On the Growth plan and above, response metrics show first and average response times, and the Responses report can be filtered by the channel a conversation opened on. A manager can check RCS against the team’s own reply target.

What RCS on respond.io supports at launch

At launch, RCS on respond.io supports two-way conversations, broadcasts, Workflows, website widgets and reporting.

Feature	What you can do with RCS	Good to know
Inbox	Send and receive text, images, video, audio and PDF files at any time	RCS has no messaging window, so there’s no 24-hour limit to work around
Broadcasts	Send RCS campaigns with text, multiple choice, file and media messages	Available on Growth plan and above
Workflows	Send messages and ask questions, including multiple choice questions, in automated flows	Available on Growth plan and above
Growth Widgets	Add an RCS Widget, a QR code or a Multichannel Widget to your website and track where Contacts come from	RCS chat links and QR codes open only on phones that support RCS, so a Multichannel Widget gives other visitors WhatsApp or Messenger instead
Reports	Filter Reports by RCS to compare RCS reply times with your other channels	Response metrics are on the Growth plan and above
Integrations	Use the Channel with the Developer API, Zapier, Make, n8n and webhooks	Webhooks are on the Advanced plan, and the rest are on Growth and above
SMS fallback	Have Twilio send the message as SMS or MMS when RCS delivery fails	Set up in Twilio by adding an SMS- or MMS-capable number to the Messaging Service your RCS Sender uses
Rich cards and carousels	Not available yet	Can’t be created or synced from respond.io, so carousel-led campaigns run outside it for now

As with any RCS sender, reach depends on each Contact’s country, mobile carrier and device. The RCS overview lists supported file types in full.

How to set up RCS on respond.io

Setting up RCS on respond.io starts in Twilio. You need a paid Twilio account and an RCS Sender that Twilio and Google approve. Every Sender needs Google registration, and US-bound Senders need an additional US registration. Carriers then approve per carrier and country, which Twilio estimates takes four to six weeks, longer if you launch in several regions. The Sender won’t appear in respond.io until at least one carrier approves it, so start the registration before you plan your first RCS campaign.

Once a carrier approves the Sender, you connect it with your Account SID and Auth Token by following the Twilio RCS quick start. Twilio bills you directly for RCS messages, with carrier fees on top, and US carriers charge onboarding fees when you launch a Sender.

On the respond.io side, rich cards and carousels stay outside respond.io, and SMS fallback is configured in Twilio. Duplicate RCS and WhatsApp profiles are merged by an agent who confirms the match, so someone has to act on merge suggestions. Automatic assignment and RCS broadcasts need Workflows and Broadcasts, which are on the Growth plan and above.

Is respond.io the right RCS business messaging platform for your team?

Respond.io is the right RCS business messaging platform for mid-market B2C businesses whose agents already answer WhatsApp, Messenger or Instagram. Respond.io’s Twilio RCS Channel puts RCS conversations in that Inbox, the Workflows Assign To Step gives each new one an owner, and merge suggestions let an agent bring a customer’s RCS and WhatsApp profiles into one Contact record. For the wider setup, read how US B2C teams manage SMS, calls, social and WhatsApp in one platform.

Respond.io isn’t the right setup if RCS is your only messaging channel and one person answers every reply, because there’s no second queue to bring together. It also isn’t the right setup if your campaigns depend on rich cards, carousels or SMS fallback managed in the same platform today.

Connect the Channel as soon as your Twilio Sender is approved. If it isn’t approved yet, start the Google and US registration first so the Sender is ready when your first campaign goes out. Create a respond.io account and follow the Twilio RCS setup steps to connect your Sender.

Frequently asked questions about RCS business messaging

Should I use RCS or SMS for customer replies?

Use RCS where your customers’ phones and carriers support it, and keep SMS for the customers RCS can’t reach. RCS is the next generation of SMS: it is built into the default messaging app on supported phones and adds a verified sender profile, images, video and files. Reach depends on the customer’s country, carrier and device, so teams that need to reach every customer keep both.

On respond.io, RCS and SMS from Twilio both land in the same Inbox as WhatsApp, Messenger and Instagram, so agents answer either one from one screen. Respond.io doesn’t switch an RCS message to SMS for you, so set up fallback in Twilio. For how SMS compares with other channels, read our comparison of SMS vs WhatsApp.

What do I need from Twilio before RCS works on respond.io?

You need a paid Twilio account and an RCS Sender that is approved and launched with at least one carrier. Every Sender needs Google registration, and US-bound Senders need an additional US registration on top of it. Carriers approve per carrier and country, and Twilio estimates four to six weeks.

Once a carrier approves the Sender, you connect it to respond.io with your Twilio Account SID and Auth Token, and RCS conversations start arriving in the same Inbox as your other channels. Mid-market B2C teams with an approved Sender can connect it as soon as it appears in the Sender list; teams without one should start the Twilio registration first.

Does respond.io fall back to SMS when RCS isn’t delivered?

No. Respond.io doesn’t fall back to SMS when RCS isn’t available, so an undelivered RCS message is not automatically resent as SMS from respond.io. Fallback is set up in Twilio: add an SMS- or MMS-capable number to the Messaging Service your RCS Sender uses, and Twilio sends the message as SMS or MMS when RCS delivery fails.

This matters if your campaigns must reach customers whose phones or carriers don’t support RCS. Teams that rely on fallback today should configure it in Twilio before moving RCS campaigns to respond.io.

Who bills for RCS business messages on respond.io?

Twilio bills you directly for RCS messages, on a pay-as-you-go basis, with no additional RCS charges from respond.io. Carrier fees are charged on top of Twilio’s rates and vary by the recipient’s carrier, and US carriers charge onboarding fees when you launch an RCS Sender. These appear in your Twilio billing.

Your respond.io plan covers the platform: the Inbox, assignment and Contact records that RCS shares with your other channels. Automatic assignment and RCS broadcasts need the Growth plan or above, because they run on Workflows and Broadcasts.

Is respond.io a CRM?

Respond.io is a customer conversation platform with CRM features such as Contact records. It works alongside the CRM you already use rather than replacing it. Each RCS conversation sits on a respond.io Contact record alongside the customer’s other channels, and that record can connect to your CRM.

For example, on the Growth plan and above, the HubSpot integration syncs HubSpot contact properties into respond.io Contact fields, so agents answering an RCS reply see the HubSpot details you choose to sync. Keep your CRM for pipeline and account data, and use respond.io for the conversations. To compare options, read our guide to the best omnichannel CRM platforms.

Is respond.io just a shared inbox?

Respond.io is a customer conversation platform that includes a shared Inbox, plus Workflows, Broadcasts, Growth Widgets and Reports, so it does more than a shared inbox. A shared inbox lets the team read the same messages, while respond.io also decides who owns each conversation and keeps one record per customer.

For RCS, that means a Workflow can assign each new RCS conversation to an agent when it opens, merge suggestions flag RCS and WhatsApp profiles that share a phone number and Reports can be filtered by RCS. A team that only needs several people reading the same RCS messages may find a simpler shared inbox enough.

Is respond.io only for WhatsApp?

Respond.io is a customer conversation platform that connects WhatsApp, Instagram, Messenger, TikTok, email, voice calls, SMS and RCS to the same Inbox, Workflows and Contact records, so it isn’t a WhatsApp-only tool.

For mid-market B2C businesses adding RCS, the RCS channel joins the channels your agents already answer, with no separate queue to staff. If WhatsApp is your only channel and you have no plans to add others, a WhatsApp-focused tool may cover what you need.

Which customers will RCS business messaging reach, including iPhone users?

RCS reaches customers whose country, mobile carrier and device all support it. Twilio lists RCS as compatible with Android and iOS 18 devices, so iPhone users can receive RCS business messages when their iOS version, carrier and country are supported.

Check Twilio’s RCS documentation for supported countries and carriers before planning a campaign. On respond.io, RCS chat links and QR codes only work on devices that support RCS, so a Multichannel Widget that also offers WhatsApp or Messenger gives customers without RCS another way to start a chat.