Palby AI Agent
Updated 10 min read

WhatsApp Business API setup: the steps, and what to decide before you start

Setting up the WhatsApp Business API isn't hard, but it's full of choices that are hard to undo: which number, direct or through a vendor, and what name your customers will see. Here's what the API does for a sales team, Meta's own steps in plain words, the limits and costs you start with, and how to tell if you need it at all.

By Leo Tan, founder of Palby AI Agent

What the WhatsApp Business API is

The WhatsApp Business API is the connection software uses to send and receive WhatsApp messages on a business number. Meta calls it the WhatsApp Business Platform, and the version you'll use is the Cloud API, which Meta hosts. There used to be a second version you ran on your own servers. Meta's On-Premises API sunset page says its last supported client expired on 23 October 2025, so a guide that asks you to choose between the two is out of date.

WhatsApp's page on its business products splits them by size. A small business uses the free WhatsApp Business app from a single device. A medium to large business uses the Platform, either directly or through a Business Solution Provider, the vendors who connect it for you.

There's no app to download for the API. You reach it through a vendor's inbox or your own code, and the customer sees an ordinary WhatsApp chat with your business name at the top.

The app or the API: what changes

WhatsApp Business appWhatsApp Business Platform (API)
CostFreeMeta charges per message delivered, plus any vendor fee
Who answersYou, on your phone and up to four linked devicesYour team, through a vendor's inbox or your own software
Starting a chatType a messageOnly an approved template, within your messaging limit
ReplyingA normal chatFree-form replies inside 24 hours of their last message
SetupDownload, register, doneA business portfolio, a Meta app, a registered number and a display name

The table hides the main difference. The app is a phone. The API is plumbing: nothing happens until software sends or receives through it.

Do you need the API?

Check this before you open a single Meta screen. The API is for businesses that send messages through software: order updates, reminders and offers to thousands of people, or many agents on one number with automation on top. Here's how the jobs a sales team does on WhatsApp split:

The jobDo you need the API?Why
Replying to enquiries and following up one to oneNoThe free Business app does this on one number
Reminders and updates sent by your booking or order systemYesSoftware sends them, as templates Meta has approved
Messaging hundreds of people who haven't written to youYesOnly templates can start those chats, within your messaging limit
Many people answering one numberUsuallyThe app is built for one phone and up to four linked devices
A bot that answers first and hands overNot alwaysSome tools link your number as a device instead, with their own risks

Plenty of small teams don't need it. If most of your WhatsApp is customers writing to you and you replying, the free WhatsApp Business app covers it, and a team can share one number through linked devices. To share one number, see WhatsApp Business multiple users, and for the full comparison of app and Platform, see what is WhatsApp Business?.

You do need it if:

  • Your own systems send the same update to hundreds of people a week.
  • More people need to answer one number than four linked devices allow.
  • You want a chatbot or automation that sends from your own software through Meta.

ActivityTracker's WhatsApp team inbox doesn't use the Platform. It links each number you use as a device, the way WhatsApp Web does, and it isn't one of WhatsApp's own apps. WhatsApp's linked devices page warns that "linking your device through unofficial apps or websites may put your account at risk", so ActivityTracker spaces out the messages a number starts on its own, and stops them if WhatsApp warns the number. The inbox shows every number you use with who's waiting, and lets you assign a chat to a teammate or leave a private note.

If what your team needs is several people answering chats, ActivityTracker's WhatsApp team inbox shows every number you use in one place, with who's waiting, assignment and private notes.

See the WhatsApp inbox

Decide these three things first

Direct, or through a vendor

You can build on Meta's Cloud API yourself, which means a developer, a server to receive messages and your own inbox. Or you use a Business Solution Provider, who gives you a signup flow and a ready-made inbox, which is the route most small businesses take. You pay their fee on top of Meta's charges, and in return nobody on your team has to write code.

Which number

Meta's page on business phone numbers says an eligible number must be owned by you, have a country and area code, and be able to receive voice calls or SMS. A registered number "cannot be used with WhatsApp Messenger", and a number already in use on WhatsApp can't be registered until that account is deleted. You also set a two-step verification PIN when you register it. A new business portfolio can register two numbers, and Meta raises the cap to 20 once the business is verified or reaches a messaging limit of 2,000.

That rule on numbers in use catches people out. If you move your current number, its app chats don't come with it. Meta does let vendors connect an existing WhatsApp Business app number and keep the app working. Its page on onboarding Business app users says you can keep sending one-to-one messages from the app, with history synced between the two, and copy up to six months of one-to-one chats across. App messages stay free. The same page lists what changes:

  • Broadcast lists are switched off, and existing ones become read-only.
  • Group chats aren't synced.
  • Disappearing messages, view once and live location are turned off in one-to-one chats.
  • Every linked device is logged out, to be linked again, and WhatsApp for Windows isn't supported.
  • The number is fixed at 20 messages per second.

Ask your vendor whether they offer it, and read that list before you say yes.

The name customers see

Every number needs a display name. Meta's display name page says it's the business name customers see on your WhatsApp Business profile, and that it should be related to your business. You don't need to finish a display name review before you start messaging, but once a review has started, any change has to be approved before customers see it. Use your real business name, the one on your website and signage.

The setup steps

The steps come from Meta's Cloud API get-started guide. A vendor runs most of them for you through their signup flow, but the order is the same.

  1. Create a Meta app and choose "Connect with customers through WhatsApp". Pick an existing business portfolio or create one; it's the account that owns your WhatsApp assets. With a vendor you skip this step and sign up through their link.
  2. Connect the app to a Messaging account. That's what Meta now calls the WhatsApp account your numbers sit under. If you created a portfolio in step 1, Meta sometimes creates one automatically, so check the API Setup panel before you make another.
  3. Send a test. Meta gives you a test number and a temporary access token, so you can message your own phone before anything is live.
  4. Set up webhooks, the address where WhatsApp sends incoming messages and delivery updates. A vendor does this for you.
  5. Create a permanent access token through a system user. Meta's guide says the temporary one "expires quickly".
  6. Add and register your real business number, with its display name and PIN.
  7. Write your first templates and submit them for review. You'll need them to message anyone who hasn't written to you in the last 24 hours.

Get opt-in before the first template

Meta's opt-in page says businesses must get opt-in before messaging people on WhatsApp. The person has to see that they're opting in to hear from you, and your business name, and the method has to follow local law. Meta lists website forms, SMS, phone and paper among the methods that work, as long as they meet those rules.

Ask once, for every kind of message you'll send: reminders, updates and offers. Meta suggests separate opt-ins by category, and an easy way to opt out that you honour. People who didn't expect your message block or report you, and that drags down the quality your messaging limit depends on.

The limits a new number starts with

A new account can't message everyone on day one. Meta's messaging limits page counts the number of different people you can reach outside a customer service window, the 24 hours after someone writes to you, in any moving 24-hour period. A new business portfolio starts at 250, and the limit is shared by every number in that portfolio, so one busy number can use it all up.

The first step up takes action from you. To reach 2,000, complete one of Meta's scaling paths: verify your business, have your vendor verify it, or deliver 2,000 template messages with a high quality rating to different people within 30 days. Meta then checks your message quality before it raises the limit. After that it scales on its own, to 10,000, then 100,000, then no limit, judged on the quality of what you send. Replies to people who wrote to you don't count against it, which is why a team that mostly answers enquiries rarely notices the cap. WhatsApp messaging limits covers how quality is judged.

Templates have a cap too. Meta's template guidelines say an unverified portfolio is limited to 250 templates per Messaging account, and a verified one with an approved display name can have up to 6,000. Verify your business in Meta Business Suite early. Verification raises the template cap and the number cap, counts as a route to the 2,000 limit, and runs while you do everything else.

What it costs

Meta's pricing page charges per message delivered, never for messages customers send you. The price depends on the message's category and the country code of the number you send to. Templates are marketing, utility or authentication; your free-form replies inside the 24-hour window are service messages.

Since 1 October 2026, each business phone number gets 1,000 free service messages a month, and Meta charges from the next one. For Singapore numbers, the rate card lists S$0.0937 per marketing message and S$0.0205 per utility message, before volume tiers. A vendor adds its own fee on top. WhatsApp Business API pricing works through a month's bill.

Template approval takes the longest

Setup can be done in an afternoon. Getting templates approved is where the days go. Meta's template review page says a decision can take up to 24 hours, and lists the common rejections: badly formatted variables, a template that starts or ends with one, asking for full card, bank account or national ID numbers, and copies of a template you already have. Mix an offer into a reminder and Meta's categorisation rules treat it as marketing. WhatsApp template rejected has each reason and its fix.

Write the three or four templates you'll send most, submit them together, and plan your launch for after they're approved.

Made-up example: a physiotherapy clinic with six staff sends 400 appointment reminders a month and answers questions on one number.

Week 1, Monday: they pick a vendor with a signup flow and a shared inbox. They keep their current number and the Business app, using the vendor's option for existing app numbers, once they've read the list of what switches off.

Week 1, Tuesday: the owner runs the signup, connects the number, sets the PIN and enters the clinic's name as it appears on the door, while the vendor sets up the webhooks behind it. The booking form gets a tick box for WhatsApp reminders.

Week 1, Wednesday: they submit three templates, a reminder the day before, a "we've moved your slot" message and a post-visit check-in. The check-in comes back as marketing. It mentioned a discount on the next session, so they cut that line and resubmit.

Week 2, Monday: all three are approved. Reminders start going out from the booking system, and the front desk answers replies from the shared inbox.

Week 4: no-shows are down because people reply to move their slot the day before. The bill is Meta's per-message charges plus the vendor's monthly fee, which the owner checks against the no-shows saved.

What to ask a vendor

Every Business Solution Provider runs the same Meta steps. What differs is the fee, the inbox and what happens when you leave. Ask each one:

  1. What do you charge on top of Meta's per-message prices, and is it a monthly fee, a markup per message, or both?
  2. Do you support existing Business app numbers, so we keep the app?
  3. Whose business portfolio will the WhatsApp account sit in? Ask for yours, so the number stays with you.
  4. How many people can use the inbox, and can we assign chats and see who's waiting?
  5. Do you help with template writing and opt-in wording?
  6. If we leave, how do we move the number and our chat history?

Mistakes that are hard to undo

  • Moving your main number without checking what happens to its chats and its app.
  • Registering a number you don't own, like a staff member's personal mobile.
  • A display name that doesn't match your business, which can fail review later.
  • Launching before templates are approved, then having nothing to send.
  • Messaging people who never opted in, who then block or report you.

What to do first

  1. Count last month's WhatsApp messages: how many you sent first, and how many were replies.
  2. Go through the list above and decide whether you need the API at all.
  3. If you do, choose direct or a vendor, and which number, before you sign up for anything.
  4. Add an opt-in line to the forms where customers give you their number.
  5. Draft your three most-used templates, check them against Meta's rejection reasons, and verify your business in Meta Business Suite while you wait.

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