Moving from the WhatsApp Business app to the API: a 14-day plan that doesn't lose your customers

Sunil Pawar sells and services water purifiers in Nashik. Eight people work for him: two at the counter, five technicians and an accountant. The shop’s number has been on the WhatsApp Business app for six years, on a phone that lives in a drawer under the billing desk, and about 4,100 customers have it saved for filter changes and service calls.

He has decided to move from the WhatsApp Business app to the WhatsApp Business API, so that both counter staff can reply and annual-maintenance reminders stop depending on someone’s memory. If you’re still deciding, read the app vs API comparison first. This plan is for the two weeks after the decision.

His worry is the right one. On the day of the switch, will customers who message the old number reach anyone?

Before day 1: what happens to the number

Three routes exist, and they differ in what you lose.

Move the same number and leave the app

Meta’s phone-number rules say a number already in use with WhatsApp can’t be registered on the Platform unless its WhatsApp account is deleted first. Meta’s migration page spells out the cost: if you delete your Business app account and register the number for the Cloud API, “your existing messaging history will be lost”, and you won’t be able to use that number with the WhatsApp Business app again unless you deregister it from the Cloud API.

Customers keep writing to the number they know. You lose the app, and with it the history on that phone. Meta tells you to back up your chats before you start. The number still works for ordinary calls and text messages.

Start with a new number

The old number stays on the app, untouched, and a fresh number goes on the Platform. Nothing is lost, and you can run both for a few weeks. The price is that 4,100 people have the old number saved, and moving them takes months of “please save our new number”. A slow move suits a business whose customers mostly arrive new each month. It doesn’t suit a repeat-service business like Sunil’s.

Keep the app on the same number (ask your provider)

Meta documents a third route, usually called coexistence. Its migration page says that if you onboard through a partner that supports Business app number onboarding, you can use the app and the partner’s software at the same time, and your messaging history is preserved. The onboarding page adds the conditions: Business app version 2.24.17 or later, a sync of up to the last six months of chats, and some changes in the app afterwards. You can’t create new broadcast lists, disappearing and view-once messages are turned off in one-to-one chats, and group chats aren’t synced.

Whether you can use it depends entirely on the provider. Ask yours in writing before you plan around it. Our provider questions include this one.

The rest of this plan assumes the first route, because it’s the one every provider can do and the one with a point of no return. If you take one of the others, skip the backup and switch-over steps and keep everything else.

Days 1 to 3: prepare while the app still runs

Nothing in these three days touches the number.

Day 1: take stock of the app. Export the chats you can’t afford to lose, starting with open service jobs and unpaid invoices. Copy your quick replies, labels and catalogue details into a document. Meta’s page only says what happens to messaging history; plan as if nothing in the app comes with you. Then list who will reply to customers after the move, and what each person handles.

Day 2: business portfolio and verification. Create a Meta business portfolio in your legal name, or use the one your ads run from, and submit business verification. You don’t need it to start. You need it because a new account can deliver to only 250 different people a day outside the 24-hour window, and verification is the usual route to 2,000. It’s also the one step whose timing you don’t control, so it goes first. The messaging limits guide explains how the limit moves after that.

Day 3: choose the provider and the name. Settle the provider, and confirm your number will sit in your own business portfolio. Choose the display name customers already know you by. Meta checks display names against its guidelines automatically once an account reaches a higher messaging limit, and allows 10 changes in 30 days, so a wrong first choice can be fixed. Aim to get it right once anyway.

Day 4: the switch-over

Pick the quietest evening of your week. For Sunil that’s Sunday after 8 pm.

1. Post a status on the app that afternoon: replies may be slow this evening.
2. Finish the backup from day 1.
3. On the shop phone, open Settings, then Account, then Delete my account, and follow the steps. Meta says it may take up to 3 minutes before the number can be registered.
4. Open your provider’s signup link. Through Meta’s Embedded Signup you log in, pick your business portfolio, verify the number with a code sent by text message or voice call, and enter the display name.
5. Message the number from a personal phone and check that it arrives in the new inbox. Reply to it.

Keep the SIM in a working phone. The number still takes ordinary calls, and the SIM is how you would receive a code if the number ever had to be verified again.

From this point customers who write to the number reach your new inbox. They don’t have to do anything.

Day 5: a payment method on your Meta account

Meta charges per delivered message: ₹0.8631 for a marketing template and ₹0.115 for a utility template to Indian numbers, before GST. Each business number gets 1,000 free service replies a month, and replies after that cost ₹0.115 each. Without a payment method, Meta delivers replies inside the free 1,000 and stops delivering after it, so add one before you depend on the number.

Indian businesses billed by Meta must move to rupee billing by 31 December 2026; the INR billing note covers that. Meta also offers prepaid top-ups by UPI. That choice is made when you first set up payment and can’t be changed afterwards, so decide before you click.

Days 6 and 7: your first templates

Outside the 24-hour window you can only send templates Meta has approved, and review can take up to 24 hours. Submit a short first set and leave a day for rejections.

For Sunil, four are enough:

• Service visit confirmed, with date and technician name (utility).
• Service completed, with the amount and a payment link (utility).
• Annual maintenance contract due for renewal (marketing).
• Filter-change offer for customers past 12 months (marketing).

The third one surprises people. Meta’s category rules treat renewal reminders as marketing, so budget 86 paise for each one, not 11.5. Our pillar guide to the WhatsApp Business API links to the category and rejection guides.

Put a “Stop offers” quick-reply button on both marketing templates.

Day 8: import contacts, with their opt-in

Don’t import the whole phone book. WhatsApp’s Business Messaging Policy allows you to message people who gave you their number and agreed to hear from you, and you should be able to show when and how each one agreed.

Split the list into three before importing:

Group	What you have	What to do
Agreed to offers	A signed service form, a ticked box, a chat where they said yes	Import with opt-in date and source
Customers, no record of consent to offers	An invoice, a service history	Import for service updates only; ask about offers after their next visit
Unknown	A number, a first name	Leave out. They’ll appear when they write to you

Sunil’s 4,100 came down to about 1,300 in the first row. That’s a smaller list than he wanted and a much safer one. The opt-in guide has wording for forms and counters, and what India’s data protection rules will ask for from around May 2027.

Day 9: set up the team

Give each person their own login, and decide who owns a new chat before the first one arrives. For eight people, two teams are enough: counter (sales, renewals, payments) and service (complaints, visits). Write the assignment rule in two sentences and pin it. Our shared inbox playbook goes through views, notes and handovers.

Remind everyone that replies are counted now. One complete answer, not four short ones.

Day 10: tell customers

If you kept the number, customers need to know very little: the name they’ll see, and that more than one person now answers. Sunil put a line on the invoice footer and the counter standee, and the team opens with their name in the first reply of each chat.

If you took a new number, use the old app while you still have it. Send a broadcast and a status with the new number, change the app’s away message to point to it, and print it on every bill. Then keep the old phone charged and checked daily for at least two months.

Days 11 to 14: the first campaign, under 250

At a limit of 250, every different person you message outside a 24-hour window counts, whether it’s a service confirmation or an offer. So the first campaign has to leave room for the day’s ordinary work.

Sunil’s first send: the filter-change offer to the 200 opted-in customers whose last service was longest ago. That leaves 50 for the day’s service confirmations.

	Maths	Meta’s charge, before GST
First campaign	200 × ₹0.8631	₹172.62
Same offer to all 1,300, later	1,300 × ₹0.8631	₹1,122.03

Send it on day 11 at mid-morning, when the counter can answer. Spend days 12 to 14 on replies, not on a second send. At 250 a day the full 1,300 would take six days of doing nothing else, which is why verification went in on day 2. At 2,000 it’s one send.

What to check at the end of week two

• Delivered and read counts for the campaign. Some marketing messages fail because WhatsApp caps how many each person receives from all businesses. Don’t resend to those people this week.
• How many people tapped “Stop offers”, and whether they were removed the same day.
• Unassigned chats at close, every day. It should be zero.
• Service replies sent so far this month, against the free 1,000.
• Template categories. Check that the two you submitted as utility were approved as utility.
• Business verification status, and whether the limit has moved to 2,000.
• Meta’s charges so far, against your own estimate.

If the unassigned count isn’t zero, fix that before the next campaign. More enquiries into a leaky inbox only loses them faster.

The checklist, to print

Before the switch

• Route decided: same number, new number, or keeping the app through a provider that supports it
• Chats backed up; quick replies, labels and catalogue copied out
• Business portfolio in the legal name; verification submitted
• Provider chosen; number confirmed to sit in your own portfolio
• Display name chosen

Switch-over evening

• Status posted on the app
• WhatsApp account deleted on the old phone (same-number route only)
• Number registered and verified through the provider’s signup
• Test message received and answered in the new inbox
• SIM kept in a working phone

Week one

• Payment method added to the Meta account, in rupees
• Four templates submitted, categories checked after approval
• “Stop offers” button on every marketing template

Week two

• Contacts split into three; only recorded opt-ins imported for offers
• Logins, teams and the assignment rule in place
• Customers told: invoice footer, standee, first-reply introductions
• First campaign to 200 or fewer, with room left under 250
• End-of-week checks done; next send planned only after the limit reaches 2,000

Start with the one item that can’t be hurried: submit business verification today, even if the switch-over is a month away. The glossary has every term used here.