WhatsApp Business API integration: a guide for business owners

The WhatsApp Business Platform lets a business send and receive WhatsApp messages from its own software through an API hosted by Meta, called the Cloud API. To use it you need a Meta business account, a phone number, a verified business, approved message templates and a server endpoint that receives messages. This guide walks through each step in the order you will meet it, with links to Meta's own documentation, so you know what to ask your vendor for.

What is the Cloud API and why does it matter?

There are two WhatsApp products for business. The WhatsApp Business app is a free phone app for one person answering chats. The WhatsApp Business Platform is the API, and the Cloud API is Meta's hosted version of it. The API is what lets your software send an appointment reminder from a patient record, deliver a lab report the moment it is signed, or route an incoming query to the right staff member. Setup means creating a Meta app, connecting a WhatsApp Business Account, registering a phone number, generating a permanent access token and configuring a webhook. Your vendor does this. You own the accounts.

What does business verification involve?

Meta asks businesses to prove they exist before scaling up. Verification is done in Meta Business Manager with documents that match your legal name and address. It affects how many people you can message. Meta's messaging limits page explains that a new account starts with a daily cap on unique contacts outside the customer service window, and that completing business verification is one of the ways to move to the next tier. Higher tiers then come automatically as you send good-quality messages that users do not block or report.

Do this early. Verification sits on Meta's clock, and a campaign planned for next week cannot wait for it.

How do templates and approval work?

Any message you send to someone who has not messaged you recently must be a template: a fixed text with numbered variables, submitted to Meta and approved before use. Meta's template guidelines set out three categories, marketing, utility and authentication, and state that review can take up to 24 hours. A template that collects many blocks or reports can be paused, so the wording matters as much as the approval.

• Utility: 'Your report for {{1}} is ready. Download it here: {{2}}.' Triggered by something the customer did or asked for.
• Marketing: 'Health check packages start this week. Reply YES to book.' Promotional, and priced accordingly.
• Authentication: one-time passcodes, in a fixed format that Meta defines.

Write templates in the language your customers read, keep variables to what you actually hold in the record, and always include a way to opt out. Templates that read like spam get rejected, and templates that get reported get paused.

What is the 24-hour window, and how is it priced?

When a customer messages you, a customer service window opens for 24 hours from their last message. Inside it, your software can send free-form text, images and documents without a template. Outside it, only approved templates are allowed. Meta's pricing page describes the window and notes that service messages inside it are not charged. Good software shows the window to staff and switches the composer to a template picker when it closes, because a message sent outside the window without a template simply fails. We built exactly this into a WhatsApp inbox for a client, and Healthixio's front desk relies on it.

Meta moved the platform to per-message pricing from 1 July 2025, according to its pricing documentation. Template messages are charged by category and by the recipient's country. Service messages inside an open window are free. Utility templates delivered inside an open window are also free. There is also a free entry point: when a customer starts a chat from a Click to WhatsApp ad or a Facebook page button, a 72-hour window opens after your first reply in which any message is free. Rates for India are listed on Meta's platform pricing page and change from time to time, so your software should show the estimated cost of a campaign before anyone presses send.

What are webhooks and why do you need them?

A webhook is the address on your server where Meta delivers events: a new incoming message, a delivery receipt, a read receipt, a failed send. Meta's webhooks documentation explains that the endpoint receives JSON payloads and that if it does not respond with a success code, Meta retries delivery with decreasing frequency for up to seven days, which can cause duplicate notifications. Your vendor must handle duplicates, keep the endpoint up, and store every event against the right customer record. This is where the message becomes part of your system instead of a chat on someone's phone.

What to ask your vendor before you start

1. Will the Meta business account, WhatsApp Business Account and phone number be in my name? They must be.
2. Who writes and submits templates, and who fixes them when they are rejected?
3. How does the software show the 24-hour window, and what happens when it closes?
4. Where do incoming replies land? They should land against the customer record, not in a separate inbox nobody checks.
5. Can I see the cost per message and per campaign before sending?
6. How is opt-in recorded, and how does a customer opt out in one word?
7. What happens when the webhook is down for an hour?

If you want this built and run for you, we do it.

Frequently asked questions

Can I use my existing WhatsApp number for the API?

A number can be registered on the Cloud API, but it then works through the API and not through the phone app at the same time. Most businesses either move their known number to the platform carefully or take a new number and announce it. Decide this before setup, because moving a number later disrupts every customer who has saved it.

How long does template approval take?

Meta's guidelines say review can take up to 24 hours, and utility templates are often faster in practice. Rejections take longer because you must edit and resubmit. Plan campaigns with a buffer of a few days, submit templates in batches, and keep a set of approved general-purpose templates ready for reminders and follow-ups.

Do I still need the WhatsApp Business app?

No. The API replaces it for the registered number. Your staff use your own software or an inbox built on the API, which can handle many people at once, assign conversations and keep history against records. The free app remains a good choice for a one-person business that does not need integration.