Connecting a WhatsApp number to a chatbot platform doesn’t have to mean giving up the Business app on someone’s phone. Meta’s own Coexistence feature keeps both running on the same number — but only some of what the app does today survives the switch, and only inside a short, one-time setup window.
What Coexistence actually keeps running
Meta calls it Coexistence: a phone already running the WhatsApp Business app can stay on its number after that number also connects to the Cloud API, with messages mirrored between both sides (Meta: onboard Business app users onto Coexistence). One-to-one chats a team still answers by hand keep working in the phone app exactly as before, while an AI Agent or a wider team answers the same number’s conversations through a platform like 1CS. The number itself doesn’t split into two — both sides see the same messages.
The sync window, and what never crosses over
Two limits decide whether this is worth doing. Meta’s own documentation gives a business exactly 24 hours after connecting to sync its existing contacts and chat history onto the Cloud API side, and the Business app has to stay open while that runs — miss the window, and the number has to disconnect and repeat onboarding. What transfers is capped too: up to six months of one-to-one chat history, and media attachments only from messages sent in the 14 days before the connection.
Some of what the app does today doesn’t cross over at all. Group chats never sync. Meta’s own feature list rules out the Business app’s catalog, order and status tools, its broadcast lists, and its greeting, away, and quick-reply messages on the Cloud API side — none of that keeps working once the number is shared this way. That’s a separate 24 hours from WhatsApp’s customer-service window, which still governs what a business can send a customer for free once connected; this one only covers the one-time sync, right after onboarding.
Set up in 1CS
1CS connects a WhatsApp number through the Cloud API, not the consumer app, so Coexistence only matters for a number that’s already answering customers from someone’s phone. From Settings > Inboxes > Add Inbox (ตั้งค่า > กล่องข้อความ > เพิ่มกล่องข้อความ), choose WhatsApp, then the WhatsApp Cloud provider, and click Connect with WhatsApp Business — that opens Meta’s own sign-in window, not a 1CS screen, and whether it offers to keep the Business app running is Meta’s call to make there, not 1CS’s. Confirm with 1CS support before relying on it for a number already active in the app, and keep that phone’s app open until any sync finishes, since the 24-hour window above starts the moment the connection completes. The Thai help center walks through the rest of the same screen in เชื่อมต่อ WhatsApp inbox; the connection itself lives inside 1CS’s unified inbox.
Since the catalog and quick-reply tools above don’t carry over, line up 1CS’s own in their place: 1CS’s commerce panel builds a cart and sends a payment-ready bill from the same conversation, which is what to point a customer to once the Business app’s catalog stops working on that number — the same tools cover sending a product list on WhatsApp without a native carousel.
A checklist to copy before you connect
Run this before anyone touches the connect button, not after a sync has already failed halfway through:
- Confirm the WhatsApp Business app on that phone is current — Meta’s Coexistence requirements start at app version 2.24.17.
- Save anything that matters from group chats on that number first — groups never sync to the Cloud API side.
- Pick a block of time when [team member] can leave the Business app open and the phone unlocked until a sync finishes.
- Tell the team the broadcast lists, greeting message, and quick replies they use today will stop working on this number once connected — line up the 1CS equivalents first.
- Start the connection from 1CS, finish Meta’s sign-in window, then send a test message from 1CS to confirm it also lands in the phone app’s chat list before calling the number “connected.”
This isn’t a reason to avoid connecting a busy number to a bigger team or an AI Agent — it’s a reason to run the sync on purpose, during a window someone is watching, instead of learning what Coexistence drops from a customer’s confused reply.
