WhatsApp Coexistence, explained 2026
What WhatsApp Coexistence is: the same number on the Business app and Cloud API at once. What syncs, what Meta bills, and when to use it.
WhatsApp Coexistence is Meta’s official way to keep the same phone number on the WhatsApp Business app and on Cloud API at the same time. 1:1 chats are mirrored. Customers keep writing to the number they already know. You can reply from the phone or from a team inbox.
Until recently the rule was binary: one number, one session. App or API. That is still true if you do a classic migration (you leave the app). Coexistence is the path that does not force you to leave it.
In ManyContacts the option is labelled Coexistence (API + mobile).
What it is (and is not)
It is:
- One business number.
- WhatsApp Business on the phone (version 2.24.17 or newer).
- That same number connected to Cloud API, with inbox, templates, AI and campaigns at your partner.
It is not:
- Two personal WhatsApp accounts glued together.
- Your app groups showing up in the inbox. Groups do not sync.
- Consumer WhatsApp. It has to be WhatsApp Business.
For the wider map of app vs API, see WhatsApp Business vs API.
Before and after
Before: moving to the API meant unlinking the number from the app. The phone stopped being the channel. The team gained an inbox; the owner lost “their” pocket WhatsApp.
Now: you can connect the number you already use in the app. WhatsApp mirrors 1:1 messages between the app and the API. Recent history (up to 6 months of individual chats, if you allow it) and contacts can sync into the panel.
A clean jump to API-only still exists. Coexistence does not replace a team that already lives 100% in the inbox. It is the bridge for people who cannot (or will not) kill the app on day one.
What syncs and what stays on the phone
| On the app and on the API | App only | Turned off or does not travel |
|---|---|---|
| 1:1 chats (in and out) | Voice and video calls | Groups (not synced) |
| WhatsApp contacts | Catalogue, orders, status | Disappearing messages, view-once, live location (on 1:1) |
| Edit / revoke on 1:1 | App tools (greeting, away, in-app labels) | Broadcast lists (read-only; you cannot create new ones) |
Linked companion devices unlink when coexistence turns on. You can re-link the ones WhatsApp still allows. Windows and WearOS are out.
Pricing and the 24-hour window
Two pipes. Do not mix them.
- Messages you send from the app stay outside Cloud API pricing. Free on Meta’s side.
- Messages you send from the API (inbox, templates, AI, campaigns) are billed at Cloud API rates.
- ManyContacts is a separate line: €49/month (3 users). Independent from Meta.
The 24-hour customer service window only applies to the API. A message in the app does not open, extend or close that window. If a customer wrote just before you connected the API, the panel may only allow a template until they write again.
Limits that matter
- 20 messages per second, fixed, on a coexistence number. Fine for a normal team. Tight for a huge blast — API-only scales higher.
- Groups, calls and catalogue do not live in the API inbox.
- An old Business app: the connect flow will not start.
- After signup there is a short window to sync history. Keep the app open and the wifi stable for that stretch.
This is not “the whole company WhatsApp in two places”. It is mirrored 1:1, plus the API for what the app is bad at: several agents, templates, metrics, AI.
Who feels it (and who should go API-only)
Coexistence fits if:
- The number “is” the founder’s or a star closer’s, and you cannot take the phone away on Monday.
- You want inbox and AI without cutting the app.
- Campaign volume is sane and 20 mps is not the bottleneck.
Prefer API-only (classic migration) if:
- Several people must live in a shared inbox, not on one iPhone.
- You run large campaigns or high-volume support.
- AI should be the 24/7 channel and the phone is noise.
If the team still answers “just in case” on the app and in the panel with no rules, you double-reply. Assign: phone for the owner’s emergencies, panel for everyone else.
How you turn it on in ManyContacts
- Create the account (7 days, no card).
- When connecting WhatsApp, pick Coexistence (API + mobile), not API-only.
- Confirm in the Business app (code + Connect to the Business Platform).
- Leave the app open while contacts and 1:1 history sync.
- Test: one message from the panel, one from the phone. Both threads should show.
You do not need a three-week project. You need the phone in hand, Business Manager, and not to cut WhatsApp mid-Saturday.
Next step
If the channel is still one Android, coexistence is the bridge. If four people already share the number, go API and a shared inbox. Create the account or book a demo and we connect the number you already have.