WhatsApp Business API: what it is and what determines the cost

There are three different things called “WhatsApp for business”, and confusing them is the cause of half the badly made quotes we have seen. One is free and cannot be automated. Another is free, can be half automated and does not scale. The third is the real platform, and it is paid for by the message.

The three things, and which one applies to you

If what you want is a system that reads and answers messages automatically, the answer is the third one. A program cannot connect in a supported way to a personal account or to the free business app; the tools that promise to do so operate outside the terms of use and expose you to having your line shut down.

That said, it does not oblige you to start with a new number. Since 2025 Meta allows coexistence: connecting to the platform the same number you already use in the WhatsApp Business app, without changing it and keeping the history synchronized between the two. It is explained in detail further down.

The July 2025 change: charging by message

For years Meta charged by “conversation”: a twenty-four-hour window inside which everything sent was included. Since July 1, 2025 the charge is per template message delivered.

The change is not an accounting one, it is a design one. Before, it paid to concentrate the conversation inside the window already paid for; now it pays to send fewer and better messages. A reminder split into three messages costs three times what the same reminder, well written, costs in one.

The three template categories

A message template is a message approved by Meta in advance; it is what you need in order to write to someone first. There are three categories and each has its own rate:

• Utility — confirmations, reminders, updates on an order or an appointment. It is the category an appointment assistant uses, and the cheapest of the ones that are charged.
• Authentication — one-time verification codes.
• Marketing — promotions, news, customer reactivation. The most expensive, and the only one with no access to volume discounts.

Meta lowers the per-message rate for utility and authentication as the monthly volume rises, aggregating the count at the level of the company's portfolio and resetting the tiers each month. Marketing does not get that benefit.

What costs nothing

This part is ignored in almost every quote, and it is the part that changes the final number the most.

• Messages that are not templates are free. Free text, images and the rest: zero.
• The customer service window. When a person writes to you, a twenty-four-hour window opens. Inside it, replying with messages that are not templates costs nothing.
• Utility templates inside that open window are also free.
• Free entry point. If the customer arrives from an ad that opens WhatsApp or from the button on a Facebook page, all the messages —templates included— are free for seventy-two hours.

The practical consequence: an assistant that only replies to whoever wrote first can cost very little in messaging, because almost all of its activity happens inside the free window. What you pay for are the messages you initiate — reminders and confirmations outside the window.

How to estimate the spend without guessing

We do not publish rates because they change by country and Meta sets them; the current list for Costa Rica is in its official documentation and it is worth looking at on the day the quote is made. What can be given is the method:

1. Count the messages you initiate, not the conversations. Reminders, confirmations, notices of a change.
2. Classify them by category. Almost all of those in an appointments business are utility.
3. Subtract the ones that fall inside an open window. If the reminder goes out while yesterday's conversation is still alive, it is not charged.
4. Multiply by the current rate for your country for that category.
5. Add the provider's margin. Meta charges its rate; the provider of the connection usually adds its own, and sometimes a monthly fee.

What you need to get started

• A phone number: either a new one that is not in use on another WhatsApp account —it can be a landline— or the one you already use in the WhatsApp Business app, via coexistence.
• A Meta business account and business verification, which asks for company documentation.
• A profile: display name, description, category.
• The templates written and approved. Meta reviews them and can reject them; it is worth submitting them with time to spare.
• A server to receive the incoming messages, or a provider that supplies one.

The test numbers Meta provides for development have strict limits —they only allow writing to a handful of authorized recipients— and they are for building, not for serving customers. Moving from the test number to the real number is an administrative step that should be scheduled, not discovered on launch day.

Coexistence: automating the number you already use

For years the answer to “can I automate the WhatsApp I already have?” was no, and it forced you to start with a new number and begin from scratch with the customers who were already writing to the old one. Since 2025 Meta allows coexistence, and that changes the calculation for many projects.

Coexistence means connecting to the business platform the same number you use today in the WhatsApp Business app, without changing it. The conversation history stays synchronized between the two, so you can carry on answering by hand from the phone while the system replies through the platform.

What you need to know before treating it as settled:

• You need the WhatsApp Business app in version 2.24.17 or later.
• Registration is done through a provider that supports this route; it is not a switch inside the app.
• A number in coexistence has a fixed cap of 20 messages per second. For an appointment book that is more than enough; for a mass send, it is not.
• Connecting it disables some features of the app: disappearing messages, view once and broadcast lists.
• What still cannot be done is connecting a program on your own to the free app or to a personal account.

The useful question to ask a provider stops being “do I have to change my number?” and becomes “do you do coexistence onboarding?”. Not all of them do.

The quality of the number, which almost nobody mentions

Meta watches how recipients react. If a lot of people block or report a number, its quality rating is lowered and with it the limit on how many messages it can send per day. At the extreme, the line is restricted.

This turns a marketing decision into a technical one: sending promotions to a purchased list not only works badly, it can also leave without service the channel you use to serve your real customers. The utility channel and the promotional channel are best thought of separately from day one.

How we can help with this

This article gives you something to read a quote with and something to estimate the spend with. What comes next —setting it up— is where the weeks go when it is discovered along the way:

• Estimating your case with your numbers, not with an example: how many conversations a month, of which category, and what part falls inside the windows that are not charged. Out of that comes a figure you can decide with.
• The full registration: business account, business verification, number —new or the one you already use, via coexistence— and the templates written so that Meta approves them first time. It is the administrative part that tends to be discovered late.
• Connecting the platform to what you already have, which is what turns the messages into something useful: your calendar, your catalog, your customer system. A number that answers without checking anything is of little use.
• Leaving it working and monitored: what happens when the system does not understand, how the conversation reaches a person, and how the quality of the number is watched before Meta lowers it.

If you want to know what spend you are facing, the technical division will review it with you in a thirty-minute meeting: what part of your messages is actually charged, which category they fall into and what you should be asking a provider. If the case is simple, the figure comes out on the same call; if it depends on data that has to be looked at carefully, it comes afterwards in writing and with the assumptions noted down, so that it can be checked. No cost, no obligation to hire us.

Frequently asked questions

How much does the WhatsApp Business API cost?

Since July 1, 2025 Meta charges per template message delivered, with rates that depend on the category of the message —utility, authentication or marketing— and on the recipient's country. Messages that are not templates are free, and so are the replies inside the twenty-four-hour window the customer opens by writing. The specific rate for Costa Rica is looked up in Meta's official documentation on the day the quote is made, because it changes.

Can I automate the WhatsApp I already use in my business?

The number, yes; the free app on its own, no. Automating requires the WhatsApp Business Platform, but since 2025 there is coexistence: the number you already use in the WhatsApp Business app is connected to the platform without changing it, the history stays synchronized between the two and you can carry on answering by hand from the app while the system replies through the platform. You need the app in version 2.24.17 or later and to register through a provider that supports this route. What is still not possible is for a program to connect on its own to the free app or to a personal account: the tools that promise it operate outside the terms of use and risk the line being shut down.

What is WhatsApp's 24-hour window?

It is the period that opens when a customer writes to your business. During those twenty-four hours you can reply with free-form messages at no cost. Once that period has passed, writing to them again requires an approved template, and that one is charged.

Do I need a provider or can I connect directly to Meta?

You can connect directly, and that is what we do when it makes sense. An intermediary provider brings convenience —a shared inbox, reports, support— in exchange for a margin on each message and, sometimes, a monthly fee. The decision depends on the volume and on whether you already have someone to administer the integration.