WhatsApp Business API: how it works and what it costs.

The app, and the platform

The WhatsApp Business app is made for a person answering from a phone. The WhatsApp Business Platform — what most people call the WhatsApp Business API — is for software: a CRM, a booking system or an AI agent sends and receives messages on the business's number through an API. Meta hosts it as the Cloud API. Every AI agent we build for clients uses it.

Two kinds of messages

Free-form messages are ordinary replies — text, images, voice notes, documents. They can only be sent inside a customer service window.

Template messages are pre-written messages, with variables, that Meta must approve before use. They are the only way for a business to start a conversation or to write outside a customer service window. Each template has a category: marketing, utility (an update about something the customer did — a booking, an order) or authentication (a one-time code).

The customer service window

When a customer writes to the business, a 24-hour customer service window opens. Inside it, the business can reply with free-form messages. Once it closes, only a template can restart the conversation. Meta also defines a 72-hour “free entry point” window: when a customer writes after tapping a Click to WhatsApp ad or a Facebook Page call-to-action button, and the business replies within 24 hours, that reply is free and a free entry point window opens.

How Meta charges since 1 July 2025

Meta's documentation is explicit: “Effective July 1, 2025, Meta charges on a per-message basis”, replacing the earlier conversation-based model. Only template messages are charged, and only when they are delivered. The rate of each one depends on “the template's category and the recipient WhatsApp phone number's country calling code” — so the same reminder costs a different amount in Nairobi, Paris or São Paulo.

• Free: non-template messages inside an open customer service window.
• Free: utility templates sent inside an open customer service window.
• Free: template messages inside a 72-hour free entry point window.
• Charged: every other delivered template — marketing, utility outside the window, authentication — at the rate of its category and the recipient's country.

Volume tiers and currencies

Businesses can unlock lower utility and authentication rates as their monthly volume grows; the tiers are specific to each market and category and reset every month. Meta describes these tiers for utility and authentication only. Meta publishes rate cards per market and region and bills in a list of currencies that includes USD, EUR, GBP, INR, BRL, AUD and others.

How to estimate your WhatsApp bill

No price list can be copied here without being wrong somewhere; a short method works everywhere:

1. List the messages your business sends first: reminders, confirmations, promotions, codes.
2. Give each one its category: marketing, utility or authentication.
3. Count them per month and per country of your customers' phone numbers.
4. Multiply by the rate of that category and country on Meta's current rate card, applying the volume tier you reach for utility and authentication.
5. Leave out the replies you send inside customer service windows: they are free.

What running WhatsApp agents taught us

• Design for the window. An agent that answers quickly while the customer is still in the conversation costs nothing per reply; the same answer a day later needs a paid template.
• Utility, not marketing, where it is true. A booking confirmation is a utility message; it is free inside the window, and outside it is billed at the utility rate rather than the marketing one. Categorise honestly — Meta reviews templates.
• Submit templates early. Approval takes time. A reminder flow cannot go live until its templates are approved, so they are the first thing we submit in a project.
• Consent comes first. Meta requires businesses to “obtain opt-in permission from the recipient confirming that they wish to receive subsequent messages or calls” from them. So we design the opt-in into the customer record from the start, not as an afterthought.