How to connect an existing WhatsApp Business app number to the Cloud API without losing the phone

By Qilin Software Lab Private Limited · Published 2026-10-14 · 3 min read

This is the practical version: what you need before you start, what happens in the signup window, and what to verify once the number is connected.

Before you start

The number is on the WhatsApp Business app (not the personal app) and the app is updated to a recent version.
A Facebook account that can administer, or create, the Meta Business Portfolio for the company.
The phone in hand. You will scan a code from the app.
A display name that matches the business. Meta checks it against its policy; a fanciful name delays approval.
Payment set up in WhatsApp Manager if you intend to send template messages soon. Inbound and 24-hour-window replies work without it.

The signup, step by step

In your connector's dashboard press Connect a number and choose use my existing WhatsApp Business app number. In NumberBridge this is the first button on the Connections page.
Meta's window opens. Sign in to Facebook, choose the business portfolio (or create one with the legal name and address).
Select or create the WhatsApp Business Account that will own the number.
Enter the phone number. Meta detects that it is on the Business app and shows a code.
On the phone open the WhatsApp Business app, go to Settings → Linked devices (or the prompt Meta shows), and scan the code.
Choose whether to share recent chat history and contacts with the API. For a CRM, say yes.
Finish. The window closes and the connector receives a one-time code which it exchanges for a token behind the scenes.

What the connector does next

Three API calls, all invisible to the business owner: exchange the code for a business token, read the shared WhatsApp Business Account and its phone numbers, and subscribe the account to the connector's app so Meta starts sending webhooks. NumberBridge also stores the phone number id, the display name and the quality rating, and shows the connection as live when Meta reports the number as connected.

Check these afterwards

Send a message to the number from another phone. It should show in the app and arrive at your webhook within a second or two.
Reply from the API (the dashboard's Send page is enough). The reply should appear in the app thread.
Reply from the phone. Your webhook receives a status for the message so your inbox stays in sync.
Look at WhatsApp Manager → Phone numbers: the number should show as connected, quality green.

Mistakes that break the link

Deleting the app or logging out of the phone. In coexistence the phone remains the primary device. Keep it online at least once every two weeks.
Registering the number elsewhere. A second API registration from another vendor steals the number from the first. Use one connector.
Letting the business token lapse. Tokens from Embedded Signup are long-lived but can be revoked if the Facebook user leaves the business. The connector should re-check and prompt for a reconnect; NumberBridge shows the connection as pending and offers the button again.
Changing the display name without re-review. Name changes go through Meta review and can pause template sends meanwhile.

Put software on your business number without losing the phone

NumberBridge connects an existing WhatsApp Business app number to the Cloud API in two minutes. Flat monthly fee, no per-message markup, 14-day trial.

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