WhatsApp Coexistence: Use the WhatsApp Business App and the API on the Same Number
WhatsApp coexistence connects the number you already use in the WhatsApp Business app to the WhatsApp Business Platform, so you keep replying from your phone while your team, automations and AI work on the same chats.
MonoChat Team Updated: 9 min read
On this page
- What is WhatsApp coexistence?
- How does coexistence work?
- What syncs between the app and the API?
- What changes in the WhatsApp Business app?
- Coexistence limits and pricing you should know
- Who is coexistence for?
- Coexistence vs moving your number fully to the API
- How to set up WhatsApp coexistence in MonoChat
- Sources
WhatsApp coexistence lets you use the WhatsApp Business app and the WhatsApp Business API on the same phone number at the same time. You connect the number you already use in the app to the WhatsApp Business Platform (Cloud API), keep replying from your phone, and let a shared inbox, chatbots and automations work on the same conversations. Customers keep writing to the number they know, and nobody has to delete their WhatsApp account first.
Before coexistence, moving to the API meant giving up the app on that number. This guide explains how coexistence works, what syncs between the app and the API, what changes in the app, the limits to plan for and which businesses it suits.
What is WhatsApp coexistence?
Coexistence is Meta’s name for onboarding a WhatsApp Business app number to the Cloud API without disconnecting the app. Meta’s developer documentation calls it “onboarding WhatsApp Business app users”. In practice it means one number with two front doors:
- The WhatsApp Business app on the owner’s phone (and supported linked devices), working the way it always has for one-to-one chats.
- The API, connected to business messaging software, where a team, AI assistants and workflows can read and reply to the same chats.
Replies sent from either side appear on the other side. If the owner answers a customer from the phone, the team sees that reply in the shared inbox, and the other way around.
For a quick definition you can share with colleagues, see the coexistence entry in our glossary.
How does coexistence work?
The flow is short. You start the WhatsApp connection in your messaging platform and choose to connect an existing WhatsApp Business app number. Meta then asks you to confirm in the app:
- You enter your business phone number in Meta’s onboarding window.
- Your WhatsApp Business app receives a message from Meta’s official business account asking you to connect to the Business Platform.
- You confirm in the app and decide whether to share your chat history with the platform.
- You enter the verification code shown during the flow, and the number is connected to the API.
From that moment, the number is live on both sides. Meta asks businesses to keep the app open while the first synchronization runs.
What you need before you start
- A number that is active in the WhatsApp Business app. Personal WhatsApp numbers are not onboarded this way.
- A recent app version. Meta’s documentation lists WhatsApp Business app version 2.24.17 or later.
- A Meta business portfolio and a WhatsApp Business account, which you can create during onboarding.
- Eligibility for your account and region. Coexistence is not offered everywhere, so check with your platform before you plan around it.
What syncs between the app and the API?
| Item | What happens with coexistence |
|---|---|
| One-to-one chats | Mirrored both ways: replies from the app appear in the platform, and replies from the platform appear in the app |
| Chat history | Optional. If you agree to share it, one-to-one history from roughly the last six months (180 days) can be synced to the platform |
| Media in history | Media from older chats is limited; Meta only includes media references for messages from about the last 14 days |
| Contacts | Contacts with a WhatsApp number can be synced, and later additions or edits sync too |
| Group chats | Not synced. Groups keep working only in the app |
| Linked devices | Up to four companion devices can be linked again after onboarding; WhatsApp for Windows and WearOS replies are not mirrored |
Two details are easy to miss. First, onboarding unlinks your existing companion devices, so you relink them afterwards. Second, history and contact sync are one-time steps that the platform runs shortly after you connect. If the sync window passes, Meta’s documentation says the business has to disconnect and onboard again to sync.
What changes in the WhatsApp Business app?
Most of the app keeps working, but a few features change once the number is connected to the API.
| App feature | After you connect |
|---|---|
| Broadcast lists | Turned off. Existing lists become read-only |
| Disappearing messages | Turned off in one-to-one chats |
| View-once messages | Turned off in one-to-one chats |
| Live location | Turned off in one-to-one chats |
| Edit and delete for everyone | Supported |
| Group chats | Keep working in the app, not available through the API |
| Voice and video calls | Keep working in the app, not available through the API on a coexistence number |
| Catalog, orders, status | Keep working in the app, not available through the API |
| Quick replies, labels, greeting and away messages | Keep working in the app, not available through the API |
| Business profile (name, address, website) | Managed in the app |
The biggest practical change is broadcast lists. If you used them for announcements, move that work to approved template messages sent through the API, and only to customers who opted in. Our guide to WhatsApp template message examples has ready-to-adapt wording.
Coexistence limits and pricing you should know
Throughput
Meta gives numbers that use both the app and the Cloud API a fixed throughput of 20 messages per second. That is plenty for support and normal campaigns for most small and mid-sized businesses. If you plan very large sends in short bursts, factor it into your campaign timing.
Messaging limits still apply to the API side
Template messages you send through the API count toward your business portfolio’s messaging limit, like on any API number. Verifying your business is one way to raise that limit; see our step-by-step guide to Meta business verification.
Who pays for what
- Messages sent from the WhatsApp Business app are free. Meta says they are not subject to the customer service window and do not open or change API conversation windows.
- Messages sent through the API follow Cloud API pricing, charged per message by category (marketing, utility, authentication, service) and the recipient’s country.
- The API’s customer service window opens only when a customer writes to you after onboarding. If someone messaged you before you connected, the API side can only reach them with a template until they write again.
For rates and worked examples, read WhatsApp API pricing or try the bulk messaging calculator.
Keep the phone active
Coexistence depends on the WhatsApp Business app staying active on the primary phone. Meta lists long inactivity of the primary device, around 14 days, as a reason a coexistence connection can drop. Open the app regularly, and do not re-register the number on another phone without planning for it, because that also ends the connection.
Who is coexistence for?
Coexistence fits best when the phone is part of how you sell, but one phone is no longer enough.
- Owner-led businesses where the founder still wants to answer VIP customers from the phone while staff handle the rest in a shared inbox.
- Salons, clinics, agencies and shops with a number printed on signs, cards and ads that they cannot change.
- Teams testing the API that want to add a chatbot or automation gradually instead of switching everything in one day.
- Sales teams where reps reply on the go but managers need visibility, assignment and reporting.
When coexistence is not the right choice
- You need the API features Meta does not support on coexistence numbers, such as calling through the API.
- You send very high volumes in bursts and need more than the fixed throughput.
- Your number is a personal WhatsApp number, or your region is not eligible.
- You do not want anyone replying from a phone outside your team’s workflow.
In those cases, register a number directly on the API instead. Our guide on how to get the WhatsApp Business API covers that route, and WhatsApp Business app vs API helps you decide between them.
Coexistence vs moving your number fully to the API
| Coexistence | Full API registration | |
|---|---|---|
| Keep the WhatsApp Business app on the number | Yes | No, the app account is deleted first |
| Chat history | Stays in the app; recent one-to-one history can sync to the platform | Lost from WhatsApp unless you back it up first |
| Broadcast lists in the app | Turned off | Not applicable |
| Messages sent from the phone | Free | Not possible; everything goes through the API |
| Throughput | Fixed at 20 messages per second | Scales with Meta’s standard API throughput |
| Best for | Owner-led teams that still reply from the phone | Teams that work entirely in software |
If your number is already on the API with another provider, coexistence is not the step you need. Moving an API number between platforms is a different process, explained in our guide to WhatsApp number migration.
How to set up WhatsApp coexistence in MonoChat
MonoChat is an official Meta Business Partner and supports WhatsApp Coexistence on the official Cloud API. Setup takes three steps.
1. Check your number
You need a number that is active in the WhatsApp Business app on a recent version. Eligibility depends on Meta’s policy, your account and your region; if you are unsure, contact us with your business details and we confirm the best setup path for your number.
2. Connect it to MonoChat
Create a free account at app.monochat.ai. The Basic plan includes one agent and one channel; other plans are on the pricing page. Start the WhatsApp connection, choose your existing WhatsApp Business app number and confirm the connection in the app on your phone. There is no number change and no migration. Where your setup supports it, you can import recent chat history so your inbox starts with context.
3. Add your team, AI and automation
Keep replying from your phone while the rest of the work moves into MonoChat:
- Shared inbox. Conversations arrive in the unified team inbox, where you assign an owner, add internal notes and see replies sent from the phone.
- AI replies. An AI assistant answers common questions, qualifies leads and hands the chat to a person when needed.
- Workflows. Workflow automation routes chats to departments, sends follow-ups and triggers actions in your CRM or helpdesk.
- Campaigns. Since broadcast lists are turned off in the app, send announcements as approved templates to opted-in contacts with bulk messaging.
A typical day looks like this: the owner answers a long-time client from the phone, the AI assistant handles opening hours and prices, and a new lead from an ad is routed to a sales agent who sees the owner’s earlier reply in the same thread.
Customer: Hi, do you have a slot on Saturday for two people?
AI assistant: Yes, we have 11:00 and 14:30 on Saturday. Which one suits you?
Customer: 14:30 please
AI assistant: Done. I have passed this to Elif, who will confirm by message shortly.Sources
Put this into practice with MonoChat