WhatsApp Business for multiple users: three ways to share one number

Can several people use one WhatsApp Business number?

Yes. Several people can answer customers on one WhatsApp Business number, in three ways: link extra devices to the WhatsApp Business app, connect the same number to the WhatsApp Business API while the app stays on the phone (Meta’s support channels call this coexistence), or run the number on the API and have everyone sign in to a shared team inbox such as Haiya.

Two questions decide which one fits. How many people answer customers? And do you need to know which of them said what? If the answers are “two” and “not really”, the app is enough. Once the answers are “four or more” and “yes”, it is not.

The three ways, side by side

How do linked devices work in the WhatsApp Business app?

Linked devices are the built-in way to put one WhatsApp account on more than one screen. WhatsApp’s help centre says you can link up to four devices at a time to your account, and that each linked device connects to WhatsApp on its own. You add a device from the Linked devices screen of the app on the main phone.

The main phone stays in charge. WhatsApp says you still need your primary device to register the account and to link new devices, and it disconnects a linked device after 30 days of inactivity. Some features do not work on a linked device at all: the help page lists viewing a live location, creating and viewing broadcast lists, and interacting with businesses through WhatsApp Flows.

For a shop where two people sit at the same counter, this is all you need.

Where linked devices run out

Linked devices stop being enough for reasons that have little to do with the number four:

• Nobody has a name. Every device is the same account, so neither the customer nor your colleague can see who sent a message.
• Nobody owns a chat. There is no way to say “this customer is mine”. Two people answer the same question, or each assumes the other did.
• Everybody sees everything. A linked device shows every conversation on the number. You cannot give a new hire only part of it.
• It all hangs on one phone. The main phone is the only one that can add a device, so a lost or broken phone stops the whole team from adding anyone.

What is WhatsApp coexistence?

Coexistence means using the WhatsApp Business app and the WhatsApp Business API on the same phone number. Meta calls it onboarding WhatsApp Business app users; support channels and partners often call it “Coexistence”. The owner keeps chatting from the app, and software connected through the API can read and send on the same number.

The number must be on WhatsApp Business app version 2.24.17 or higher, and the chat messages of the most recent six months can be synchronised into the connected software. Group chats are not synchronised. Meta also says messages the business sends from the app itself continue to be free, while messages sent through the API are subject to Meta’s API pricing.

Coexistence suits an owner who is not ready to give up the app, and it can be a first step. It does not take the phone out of the picture: the app on the owner’s phone stays part of the set-up. Not every inbox provider offers it, so ask yours before you plan around it.

How does a shared team inbox on the WhatsApp Business API work?

On the API, the number is not tied to one phone app. Meta describes the platform as a way to “programmatically message” on WhatsApp, with business phone numbers used for sending and receiving (About the WhatsApp Business Platform). The number is connected to software, and people sign in to that software.

In a shared team inbox like Haiya, each teammate signs in as themselves and works from their own phone, in the native iPhone and Android apps, or from the web dashboard. Three things change compared with linked devices:

• Every chat has an owner. Each customer has one owner at a time, given by an owner or admin, and the rest of the team can see who it is.
• Everyone sees only their part. Each person has a role (admin, agent or viewer), and you choose which numbers each teammate works on. A viewer can read chats without answering.
• The team can talk in private. A team thread sits beside each customer chat, for notes and hand-overs. The customer never sees it.

The API’s limits are about volume, not seats. Meta’s messaging limits cap how many different people a business can deliver messages to in a moving 24-hour period, starting at 250 for a newly created business portfolio, and Meta raises the limit as a business completes one of its scaling paths.

What does each option cost?

The WhatsApp Business app and its linked devices carry no Meta message charges. The API does, and on the API the costs come from two places.

Meta charges for messages. Meta charges per delivered message, and the rate depends on the message category. A 24-hour customer service window opens when a customer messages or calls you. Each business phone number has a monthly free tier of service messages.

Your inbox software charges for the team. With Haiya you pay one plan for the team, you pay Meta directly for messages, and Haiya adds no markup to Meta’s fees. The plans, their team sizes and the free trial are on Haiya’s pricing page.

How to move a team onto one WhatsApp number

These five steps work whichever inbox you choose.

1. Count who answers customers, and when. List everyone who replies, including the people who only cover weekends. That number, not your headcount, is what your plan has to fit.
2. Decide whether the app stays. If the owner wants to keep WhatsApp Business on their phone, read Meta’s list of what switches off under coexistence first. If nobody needs the app, connect the number to the API on its own.
3. Connect the number. Follow the number set-up in your inbox software, and give Meta a payment method for message charges.
4. Invite each person with their own sign-in. Give everyone an account and a role. Use a read-only role for people who need to see chats but should not answer.
5. Agree one rule about ownership. A simple one works: whoever answers first owns the customer, and hand-overs happen in the team thread, never in the customer’s chat. Then log out the old linked devices.

Which option should you choose?

Stay on linked devices if two to four people work in the same room and can call across it. Use coexistence if the owner wants to keep the app while the team starts working from shared software. Move to a shared team inbox when people work shifts or in different places, when customers are handed from one person to another, or when you need to see who promised what.