Migrating Your Existing Number to the WhatsApp Business API

Yes, you can keep your existing number, and there are two different ways to do it. The one you pick changes everything below, so it is worth deciding before you touch anything.

This page is about the first one. If you would rather keep using the app on your phone while the same number also works through the API, that is coexistence, and it is a different setup with different trade-offs.

For a full migration, the fact that drives everything is that the number leaves the phone app when it connects. Migration is not difficult, but it is one-way in practice, and doing it in the wrong order means a day where customers message a number nobody is watching.

What moves, and what does not

The two that hurt are chat history and labels. Export any conversation you need for records before you start, because after a full migration the app will no longer open on that number.

The safe order of operations

1. Export what you need. Chat history for anything contractual, and your contact list as a spreadsheet with numbers in full international format.
2. Decide whether to migrate at all. Connecting a second number first is slower but carries no risk, and lets you learn the platform before your main line depends on it.
3. Prepare your templates. Write the two or three you know you need — order confirmation, delivery update — so you can submit them the moment the number connects. Approval is usually minutes to a few hours; read why templates get rejected first.
4. Pick a quiet window. Early in your slowest day. Not before a sale.
5. Delete the WhatsApp Business account on the phone for that number, which releases it. This is the irreversible step.
6. Run embedded signup and verify the number by SMS or call — the process in how to get the WhatsApp Business API.
7. Set your profile and submit templates immediately.
8. Send yourself a test from another phone, both directions.
9. Update every link that points at the number — website button, Instagram bio, Google Business Profile, QR codes on packaging.

Steps 5 to 8 take under an hour in practice. The risk window runs from deleting the account to completing signup, which is why step 4 matters.

What your messaging tier will be

Migrating carries over no sending reputation from the app, because the app had no tier. You start where every new business portfolio starts: 250 unique customers in a rolling 24 hours, with the ladder running 250 → 2,000 → 10,000 → 100,000 → unlimited as volume and quality allow — see Meta's messaging limits documentation.

For a store that mostly answers customers this rarely bites, because replies inside an open 24-hour window do not count against the tier at all. It matters if your first act after migrating is a large campaign, which is a bad first act anyway — and verifying your business is the fastest way to reach 2,000. See messaging limits and tiers explained.

What to check the morning after

1. Send and receive a real message from a phone that is not yours.
2. Check your display name has been approved — review takes minutes to 48 hours, and until it clears customers see the number rather than your name.
3. Confirm your templates are approved and send one to yourself.
4. Click every link that points at your number — website, Instagram bio, Google Business Profile.
5. Watch the inbox for an hour at your busiest time, to be sure nothing is arriving somewhere nobody is looking.

If something has gone wrong it shows up in the first two. Meta's error code reference covers what any failure message means, and our guide to WhatsApp error codes for merchants translates the common ones into plain English.

The mistakes that cause real damage

Migrating the day before a sale. Template approval, display-name review and your own learning curve all want slack. Give yourself a week.

Forgetting the printed links. The number still works, so packaging is fine — but a wa.me link with a prefilled message is worth re-checking, and any link pointing at a number you abandoned is dead.

Assuming customers notice. They do not, and that is good: to a customer nothing changes. Do not announce a migration.

Not exporting first. The one irreversible mistake on this list.

Expecting to reply to old conversations. After migrating, the 24-hour window applies to every conversation, and threads from the phone are not open. Anyone you were mid-conversation with must message you again, or be reached with an approved template.

Migrating between platforms, not from the app

If your number is already on the API with another provider, this is a different and easier job. The number belongs to your Meta Business Account rather than to the vendor, so what moves is which platform is connected to it.

Templates live on the WhatsApp Business Account and generally survive. What does not survive is your flows — no two builders share a format, so a complex chatbot is a rebuild rather than an export — and your chat history, which stays with the old platform.

The safe sequence has the same shape: build your two most important flows on the new platform against a test number, then move the connection during a quiet window.

Should you migrate at all?

If you are a solo operator answering a handful of messages a day, the honest answer may be no — see the Business app versus the API for the three cases where staying put is right.

If two or more people answer customers, or you want automation or campaigns, migration is the only route and the cost of delaying is a team sharing one phone. Connect a second number this week, learn the platform, and move the main line when you are comfortable.

What changes the day after you migrate

The mechanics get covered elsewhere; what surprises merchants is the change in how sending works. Three things are different from the first hour.

The first row is the adjustment. Outside a 24-hour customer service window, Meta only permits pre-approved templates — so the "just message them" habit from the app does not carry over. The window opens when a customer messages or calls you and resets each time, per Meta's documentation, and everything inside it is free.

The third row corrects a figure people carry over incorrectly. The 256-contact limit is an app limit, not an API one, and it also only ever reached people who had saved your number. On the API, reach is set by your messaging tier instead — starting at 250 unique recipients per rolling 24 hours and rising through 2,000, 10,000, 100,000 and unlimited.

Get these three right before you move the main line

1. Templates approved for your core order messages. Confirmation, shipping and any cancellation notice. Approval takes anywhere from minutes to more than a day, so do it before you need it.
2. Business verification started. It raises your template ceiling from 250 to 6,000 and is the fastest route from a 250-recipient tier to 2,000. See messaging limits and tiers.
3. Consent collected separately for order updates and marketing, which is both the legal position in most markets and the thing that keeps your quality rating green. See opt-in rules.

The first automation to build afterwards

Not a campaign. The flows worth having on day one are the free ones: an order confirmation that asks the customer to confirm rather than announcing, a shipping notification, and a reply for messages arriving outside your hours.

All three are utility or service messages, which are free inside an open conversation window, deliverable everywhere, and welcomed rather than tolerated. Building your first automation walks one through from an empty canvas.

The week after

Two habits worth adopting immediately, because both prevent problems that are hard to unwind later. Keep an eye on the automation activity view for the first few days — a flow that never runs is far more common than one that misfires, and the cause is usually a keyword list rather than the migration. And check your quality rating weekly from the start, so you learn what normal looks like before you have a problem to diagnose.

Tell your customers nothing

There is no need to announce a migration. From the customer's side the number is unchanged and messages keep arriving; explaining the plumbing invites questions nobody had.

Plan it for a quiet week rather than a busy one.