Multiple users on WhatsApp: how to run one number with several agents

To have multiple users answer the same WhatsApp number, you have two paths: link several devices to the WhatsApp Business app, or connect the number to the official WhatsApp Business API and use a multi-agent platform. The first option is free and works for two or three people sharing everything. The second is built for teams that need to split chats, know who handled whom and measure results.

This guide compares both options, lays out their real limits and shows how to organize a team that sells and supports customers on WhatsApp.

Why one phone stops being enough

Most businesses start the same way: one phone, one number, one person answering. It works until one of these happens:

• More messages come in than one person can answer on time.
• The team grows and several people need to reply.
• There are shifts, and the phone gets passed around.
• Nobody knows who promised what to each customer.
• The owner has no way to measure how long the team takes to respond.

At that point, the question is no longer whether you need multiple users, but how to get there without losing control.

Option 1: linked devices in the WhatsApp Business app

The WhatsApp Business app (and regular WhatsApp) lets you link extra devices to your account: WhatsApp Web in a browser, the desktop app or a tablet. They all show the same conversations as the main number.

How it works

1. Open WhatsApp Business on the main phone.
2. Go to the linked devices option.
3. Scan the QR code shown on WhatsApp Web, the desktop app or the tablet.
4. From then on, that device shows and sends messages from the same number.

Linked devices can keep working while the phone is offline, but the main phone needs to connect every so often to keep the session alive, and the number of devices you can link is limited.

Pros

• It is free and takes minutes to set up.
• No need to change numbers or tools.
• You keep the app’s features: labels, quick replies, away messages and catalog.

Limits

• Everyone sees everything. There are no per-agent inboxes and no way to assign a chat to one person.
• Double replies or forgotten chats, because two people answer the same customer or each assumes the other did.
• You cannot tell who replied. To the customer and to you, everything came from “the business.”
• No per-person metrics: no response times, no sales by agent.
• Security risk: anyone with access can delete chats, and when someone leaves you have to remember to unlink their device.
• No advanced automation such as auto-assignment, flow-based chatbots or segmented campaigns.
• Device cap: it does not scale beyond a small team.

If you are still choosing between the apps, read WhatsApp vs. WhatsApp Business.

Option 2: WhatsApp Business API with a multi-agent platform

The official WhatsApp Business API has no app of its own. You use it through a provider that connects your number to a platform. There, each agent logs in with their own user, sees the conversations assigned to them and works from the web or a phone. The number no longer depends on a physical device.

How it works

1. Connect your number to the API through a provider such as Mercately, an official Meta Partner.
2. Create a user for each agent and organize them into teams (sales, support, collections).
3. Set assignment rules: by team, workload, schedule or tag.
4. Every new chat reaches the right person, with the customer’s full history.
5. A supervisor sees every conversation, reassigns when needed and reviews reports.

The full setup is in our tutorial to connect the WhatsApp Business API to Mercately.

Pros

• Each agent has their own inbox and login, so you know who handled every conversation.
• Automatic assignment and manual reassignment, so no chat is left orphaned.
• Shared history: if an agent is out, someone else picks up without asking the customer to start over.
• Metrics on response times, conversations and workload per agent.
• Automation: chatbots, AI agents, welcome and after-hours messages.
• Campaigns with Meta-approved templates to reach your customers.
• Access control: grant and revoke permissions without touching a phone.

What to keep in mind

• Meta charges for delivered messages based on category and the recipient’s country. Estimate your spend with the WhatsApp API pricing calculator.
• To message a customer outside the 24 hour window you need approved templates.
• The platform has a monthly cost depending on the plan.

Comparison: app with linked devices vs. multi-agent API

How to organize a team on one number

The tool is half the job. The other half is the process:

1. Define teams and owners. For example, sales for new leads, support for customers with orders and collections for payments.
2. Pick an assignment rule. Round robin to split evenly, by workload so nobody is swamped, by schedule for shifts or by tag if each agent specializes in a product.
3. Use a chatbot as your front desk. Let it ask what the customer needs and route them to the right team. Our WhatsApp chatbot guide has ideas.
4. Standardize answers with quick replies, but leave room for a personal touch.
5. Tag every conversation to segment campaigns and see which inquiries convert best.
6. Set response time goals and review them weekly with the team.
7. Review permissions whenever someone joins or leaves the team.

Multi-agent is not the same as multi-number

These are two different needs that often get mixed up:

• Multi-agent: several people answer one number. That is what this guide covers.
• Multi-number: one account manages several WhatsApp numbers, for example one per branch, country or team, with routing and reporting per number.

If you run several branches or brands, you may need both. With Mercately you can combine them using the multi-number CRM.

How Mercately helps

Mercately’s WhatsApp Multi-agent lets several agents answer the same WhatsApp Business API number, each with their own inbox, with automatic assignment by team, workload, schedule or tag, manual reassignment and central supervision. Unlike the app’s multi-device mode, Mercately uses the official WhatsApp API as an official Meta Partner.

Plus:

• Omnichannel inbox: WhatsApp, Instagram and Facebook Messenger in one place, with each customer’s full history. Explore the CRM.
• MIA, the AI agent, answers 24/7, qualifies leads and hands off to an agent when needed.
• Smart AI suggestions so your team replies faster.
• No-code chatbots to greet, qualify and route every inquiry.
• Analytics on response times, conversations, agent workload and sales.
• Mobile app for iOS and Android, plus the web version, so your team can work from anywhere.
• Guided setup with support from the Mercately team.

To see how multi-agent fits into a full sales process, read our WhatsApp CRM guide or check the plans.

Conclusion

If two or three people answer and volume is low, the app’s linked devices can do the job for a while. Once you need to split chats, know who served each customer, automate and measure, pairing the official API with a multi-agent platform is the natural next step. The key is making the jump before the chaos starts costing you customers.

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