WhatsApp for business: the app, the API and when a chatbot is worth it.

The short answer

WhatsApp has two products for businesses. The WhatsApp Business app is free and runs on one phone. The WhatsApp Business Platform, usually called the API, has no app of its own: messages go through software, and Meta charges for them.

Most small businesses should start with the app and stay there until the phone becomes the bottleneck: several people need to answer the same chats, reminders should go out from the booking tool, or a chatbot should answer at night. Then the API earns its cost.

In Europe there is one more thing to settle before you install the app on a work phone. It can upload the phone's address book to WhatsApp, and on a business phone that address book is full of customers. That is the GDPR problem covered below.

The WhatsApp Business app

The app costs nothing and runs on one phone with your business number. It adds what a shop, a studio or a clinic needs on top of ordinary WhatsApp:

• A business profile with your address, opening hours and website.
• A catalogue of services or products with prices.
• Quick replies for the answers you type every day.
• A greeting for people who message you for the first time, and an away message outside your hours.
• Labels to sort chats, such as new enquiry, booked or paid.

A few colleagues can link the account on their own devices, so more than one person can reply.

Where it runs out: there is no proper shared inbox with an owner for each chat, no connection to your booking tool or CRM, and no automation beyond the greeting and away messages. Everything lives on one phone, so that phone and its backups hold your customer conversations.

The WhatsApp Business Platform, or API

On the platform, messages go through software: a shared inbox, your CRM, a helpdesk, your booking tool or a chatbot. You connect through Meta's own Cloud API or through a provider such as Twilio, which adds its own charge per message on top of Meta's.

What it adds: several people in one inbox with owners and history, messages saved to customer records, reminders sent by your booking tool, and chatbots. What it asks for: a Meta business account, a phone number for it, message templates approved before you start conversations, and a budget for each message.

A number moved to the platform used to stop working in the app. Meta now lets eligible businesses connect a number that is already on the Business app and keep using the app alongside, which providers call coexistence. Ask your provider whether your number qualifies before you move anything.

The 24-hour window and templates

Two rules shape everything on the platform. When a customer messages you, a 24-hour customer service window opens, and each new message from them restarts it. Inside the window you can reply in your own words. Outside it, you can only send an approved template.

A template is a message written in advance with gaps for the details, such as a name or a time. Each one is reviewed before you can use it, and each sits in one of three categories: marketing, utility for things like confirmations and reminders, and authentication for login codes. A template that customers keep blocking or reporting can be paused.

Two templates for a physiotherapy clinic:

• Utility: "Hello [name], this is a reminder of your appointment at Harbourside Physio on [day] at [time]. Reply here if you need to change it."
• Marketing: "New Pilates classes at Harbourside Physio on Tuesday evenings. Reply BOOK and we will send the times."

Write utility templates as plain facts about something the customer booked or bought. A reminder with an offer added becomes a marketing template, and is charged as one.

How Meta charges, and what decides your bill

The app is free. On the platform, Meta's charges work like this:

• Since 1 July 2025, Meta charges for each delivered template message. The price depends on the category and on the country of the customer's number.
• Since 1 October 2026, replies inside the customer service window are free only for the first 1,000 a month on each business number. After that, they are charged too.
• Messages customers send you are never charged.
• Utility and authentication templates get lower rates at higher monthly volumes.
• A conversation that starts when someone taps a Click to WhatsApp ad opens a free window for a while.

Add your provider's charges and any inbox or chatbot software on top. Meta publishes its current rates by country on its developer site, and they change, so check them before you set a budget.

A worked example. A physiotherapy clinic in Valencia sends 400 appointment reminders a month, all utility templates, so 400 charged messages. Patients reply to confirm or to ask about parking, and the clinic sends around 600 replies inside the window, within the free 1,000. Once a quarter it sends one marketing template about classes to 300 patients who agreed to offers. Its bill is the reminders every month, plus the campaign in the months it sends one. The replies cost nothing until the clinic passes 1,000 in a month.

Get opt-in before you message first

Meta requires opt-in before you start a conversation with anyone. The person must agree to receive messages from your business by name, and you must also follow local law. The opt-in does not have to be a WhatsApp-only tick box, but it has to be clear.

Collect it where you collect the number. Two boxes, both unticked, for a booking form:

• "Send my booking confirmation and reminders on WhatsApp from Harbourside Physio."
• "Send me news and offers from Harbourside Physio on WhatsApp. I can stop at any time."

Keep them apart. Reminders and offers are different categories on WhatsApp, and Europe's marketing rules treat offers more strictly than reminders. Ask your adviser how your country's rules apply to marketing on WhatsApp.

A customer who writes to you first has opened the window themselves, and you can answer them freely for 24 hours. That does not make them a subscriber to your offers.

The contact upload problem in Europe

The WhatsApp app, the business version included, can upload the phone's address book to WhatsApp on a regular basis. WhatsApp's own privacy notice says this covers your contacts who do not use WhatsApp too, whose numbers it keeps in hashed form. On a work phone those contacts are your customers, and under the GDPR your business needs a lawful reason to share their numbers.

At least one German data protection authority, Lower Saxony's, has said that sending the address book to WhatsApp is usually unlawful, and that using the app without it means switching off contact access straight after installing, which makes the app awkward to use.

If you stay on the app:

• Use a phone that belongs to the business, not anyone's personal phone.
• Do not give WhatsApp access to the phone's contacts, or keep customers out of that phone's address book.
• Never add customers to a group, where every member sees everyone else's number.
• Say in your privacy notice that you use WhatsApp, for what, and who else processes the messages. The GDPR checklist for small business websites covers the rest of the notice.
• When the volume grows, move to the platform, which runs through software and has no phone address book to upload.

This is general information, not legal advice. Your data protection adviser can tell you what your own authority expects before you put WhatsApp on a work phone.

When a WhatsApp chatbot is worth it

A chatbot on WhatsApp needs the platform, and every reply it sends counts towards your messages. It is worth building when:

• Customers already message you on WhatsApp in numbers you cannot answer by hand.
• Most messages ask the same things: prices, opening hours, free slots, parking.
• Many arrive in the evening and at weekends, when nobody is in.
• Booking requests can be taken in the chat and passed to your team or your booking tool.

It is not worth it for a handful of messages a day, or when nearly every message needs a person's judgement, such as a clinic where most chats describe symptoms. Quick replies in the free app do that job for nothing.

Meta's terms have barred general-purpose AI assistants from the platform since January 2026. A business's own chatbot that answers its customers and takes their bookings is the kind of use the platform still allows.

Wherever it runs, the same rules apply as on a website: it answers only from information you approve, says when it does not know, and hands the chat to a person in the same thread, as what a chatbot should hand over describes. The chatbots GGSites builds start on your website. Other channels, WhatsApp included, depend on each platform's rules and approval, so we check them case by case.

One salon, three stages

A two-chair hair salon in Valencia shows how the choice grows over time.

First, the owner installs the Business app on the salon's own phone. She sets a greeting, an away message for Sundays, the price list as a catalogue and quick replies for the five questions she gets every day. Contact access stays off.

A year later, two stylists answer WhatsApp between clients, messages get missed and reminders are typed by hand. The salon connects its number to the platform through a provider, keeps the app on the same number, and uses a shared inbox where each chat has an owner. Reminders now go from the booking tool as utility templates.

Then she notices that half the messages arrive after closing, asking for prices and a free slot. A booking chatbot answers from the approved price list, takes the booking request and leaves it for the front desk, which confirms in the morning. Each step came only when the one before stopped working.

Moving from the app to the platform

Plan the move before you touch the number. In this order:

• Choose how you will connect: Meta's Cloud API through your own software, or a provider with a ready-made shared inbox. A small business usually wants the second.
• Check whether your number can use coexistence, so the app keeps working alongside. If it cannot, agree who loses the app on the day of the move.
• Write your templates first: the confirmation, the reminder and anything else you will send outside the window. Each needs approval before it can go out.
• Decide who owns each chat in the new inbox, and who covers evenings and days off.
• Collect opt-in for the messages you will start, if you did not before. Customers who write to you can still be answered inside the window.
• Save anything you need from the old chats, such as booking details, before a full move.
• Tell the team the date, and test with your own phones before customers notice anything.

If reminders will come from your booking tool, check that it can send WhatsApp templates at all, and switch off its text or email reminders for those customers, so nobody gets the same reminder twice.

Mistakes to avoid

• Running the business on a stylist's or an engineer's personal WhatsApp. When they leave, the chats leave with them.
• Broadcasting offers to everyone in the phone. People block and report you, and a number with many reports can be restricted.
• Writing a marketing message as a utility template to pay less. Templates are judged by what they say.
• Promising WhatsApp replies at night with nobody behind them.
• Copying customer numbers into the phone's address book so their names show in WhatsApp.
• Letting the 24-hour window close on a customer's question, then needing a paid template to answer it.

What to do first

Count the WhatsApp messages you get in a normal week: how many, when they arrive and what they ask. If it is a few dozen and one person answers them, set up the free app properly on a business phone and stop there.

If it is more, or several people answer, price the platform with a provider using Meta's current rates for your country and the number of reminders you send. If most messages repeat the same questions, read how to add an AI chatbot to your website first. Collecting the questions and approving the answers is the same work on WhatsApp. For the other Meta inboxes, see automating Instagram and Facebook messages.