A WhatsApp chatbot is a program that answers the messages arriving at your company's number on its own. Built properly it does four things: answer the question you get asked forty times a week, take the details of whoever writes at eleven at night, say where an order has got to, and hand the conversation to a person the moment it gets complicated. Look hard at anything beyond that.
And here's something you won't find in the top Google results: since 2 August 2026 you can no longer disguise the fact that it's a bot. Article 50 of the EU AI Act requires you to tell whoever is on the other side. So the question has changed: it's no longer about sounding like a person, it's about not wasting their time. That's what annoys people, robot or no robot.
What a WhatsApp chatbot actually does
The rule fits on one line: automate whatever always gets the same answer. As soon as the answer depends on the case, you need a person. That holds for WhatsApp and for any other AI automation.
- ✓What you already answer by copy-paste. Opening hours, address, whether you deliver, whether that item is in stock.
- ✓What comes in out of hours. Not to resolve it, but to take the name and the need, so it's on the desk at eight in the morning.
- ✓The “how's mine coming along?”. The status of an order or a repair: from what we see, the one that eats the most time and gains the least from being answered by hand.
- ✓The screening beforehand. Asking what they need and by when, so whoever picks up the thread doesn't start from zero.
Best left alone: bespoke quotes, complaints and any message that delivers bad news. A bot saying no is a fast way to lose a customer who could still have been saved.
Automate whatever always gets the same answer.
Since August you have to say it's a bot
Regulation (EU) 2024/1689, the European AI Act, applies in stages: some obligations came earlier and others don't land until 2027. 2 August 2026 is when general application begins, and that's the one that brings this in. Its article 50 requires anyone talking to an AI system to know it, unless it is obvious from the context.
Watch that exception, because it's the gap everyone will try to slip through. AESIA, the Spanish body that supervises this, warns that it “must be interpreted narrowly”: assuming everyone already knows bots exist doesn't work as an excuse.
The duty to design it that way falls on whoever builds the tool, but you're the one facing your customer. It's solved with one sentence in the first message: “Hello, I'm the automated assistant at Talleres Pérez. If you'd rather speak to a person, type HUMAN.” That is the usual way of meeting the article 50 information duty; the rest depends on what you use the system for, and this is no substitute for having your adviser look at it.
On fines, let's deflate the balloon a little: people talk about up to €15 million or 3% of worldwide turnover, which is true for a multinational. For SMEs, start-ups included, article 99 applies the lower of the two figures, not the higher.
No hype: saying so isn't just covering yourself. The customer doesn't mind talking to a bot if it sorts them out, and takes it very badly to find out after ten wasted minutes.
Before building anything: does anyone message you on WhatsApp?
It's the question none of the sites at the top wants to ask. On 31 August 2026 we looked at page one of Google in Spain for “chatbot para whatsapp”: all eight organic results are from companies that sell chatbots —five product pages and three articles signed by vendors—. Nobody with that P&L is going to tell you that you might not need one. We sell it too, for the record: which is why the method and the sources are dated.
That same day we looked at our own systems. Of the 52 websites we host, at least 34 have a WhatsApp button: it's the default channel among the small businesses we work with, consistent with 94.6% of internet users using it, according to the CNMC household panel for the fourth quarter of 2025. Of those 34, eight have Analytics with data and we checked them one by one: only two measure whether anyone actually clicks it. On the other six there's no event logging the click at all, so nobody can know whether it gets used. The funnel this comes from: 52 hosted sites → 34 with a button → 8 with Analytics → 2 that measure it. These are our clients, not a market sample.
In one of those two businesses (an industrial manufacturer, a single case), this is how interactions split across its contact channels over three months:
Contact channels for a single business, 94 in total, from 1 June to 30 August 2026, measured in Google Analytics 4. The four bars are not measuring the same thing: WhatsApp, email and phone count clicks on the link —not conversations or calls—, while the form bar counts completed submissions, which ask a good deal more of the visitor. The mix favours the first three, WhatsApp included.
Even with that caveat, WhatsApp takes more than half. In another business it might come out the other way round, which is why the first step isn't signing up for anything: tag the click in Analytics and wait a month. Same as when you pull reports out of the data you already have: look first, decide afterwards. If it comes back with four clicks, you have your answer and you've saved yourself the subscription.
The free app doesn't build bots
The WhatsApp Business app, the free one, only has three automations: a welcome message, an away message and quick replies, which you fire off by hand anyway. For many businesses that's enough, but it isn't a chatbot: it doesn't understand what people write to it.
A bot needs the WhatsApp Business Platform (formerly the API), which you sign up for through a Meta-authorised provider, with a business portfolio and a dedicated number. Careful with the number: according to Meta's documentation on business numbers, one already in use in the app cannot be registered without deleting it first. But don't delete it yet: first ask your provider about coexistence, the route that registers a number already in the app without taking it out. Meta keeps messages synced between the two and carries over the last six months of conversations, not the entire history. It depends on your provider having set it up, so you have to ask. Deleting the number you've always used to start from scratch is the classic disaster, and often an avoidable one.
One detail that's rarely explained properly: according to Meta's messaging limits, checked on 31 August 2026, the cap applies per business portfolio, not per number, and every number inside it shares the same allowance. You start at 250 unique customers you can open a conversation with every 24 hours. Verifying the business is the most direct way to raise it, but not the only one. And replying to people who write to you doesn't eat into that cap.
Replying is free; writing first costs money
This decides whether it comes out cheap or expensive. Since 1 July 2025 Meta charges per message, not per conversation.
When a customer writes to you, a 24-hour window opens: inside it you can reply as much as you like and pay nothing. Outside it, only approved templates fit, and the marketing ones are all charged.
Translated onto your bill: a bot that serves the people who write to you generates no messaging cost inside that window; one that chases people with promotions is the one that runs the bill up. On top of that comes the monthly fee of whichever provider you build it with. If you do end up building it, fit it in with the rest of the processes you automate, not as a loose part. We're not quoting figures in euros because Meta's rates change by country and category, and every provider's are different. Ask three things before signing: minimum fee, whether they add a margin on top of Meta's price, and what happens to your number if you cancel.
And before sending anything promotional, article 21 of Spain's LSSI requires prior consent, with one exception worth knowing: if that person has already bought from you, you may write to them about products or services similar to the ones they bought, provided you obtained their number lawfully and give them a simple, free opt-out in every message. For everything else —a bought list, or something unrelated to what they bought— you need them to have said yes.
What gives a badly built bot away
Since you have to declare it anyway, at least make it a decent one. What makes people hate them is almost never the technology:
- ✓There's no way out. The menu goes round in circles and the option to talk to someone never appears. It's the fault we come across most.
- ✓It asks for details it already has. The customer has been buying from you for three years and the bot asks their name.
- ✓It promises what it can't control. “We'll call you right back” and nobody calls.
A Gartner survey published on 4 August 2026, covering 3,566 customers, found that 87% want the option of reaching a human to remain if AI is handling the conversation. They don't reject the bot: they reject being locked inside it.
Where to start
Take the question you get asked most and automate only that one. And read the chats in full for the first week: that's where you see what your customers actually ask, which is almost never what you thought, and what decides whether the bot is helping or getting in the way.
And if you also want it to do things, like putting the appointment in the calendar, we're no longer talking about a chatbot but an AI agent: we cover that in our article on agents.
Frequently asked questions
What is a WhatsApp chatbot?
It's a program connected to a company's WhatsApp number that answers incoming messages automatically. It's used for the repetitive stuff: opening hours, prices, availability, the status of an order, or taking the details of anyone writing outside business hours. Since 2 August 2026, article 50 of the EU AI Act requires you to tell the person they are talking to an automated system, unless it is obvious from the context.
How do you set up a chatbot on WhatsApp?
In four steps: get a phone number that isn't registered in any WhatsApp app, create a business portfolio on Meta, sign up for the WhatsApp Business Platform through an authorised provider and, once inside, map out the conversation flow. The step that causes the most trouble is the first: a number already in use in the app can't be registered without deleting it first. Ask your provider about coexistence before deleting anything: it registers that number without taking it out of the app, with messages synced between the two and the last six months of conversations. It depends on your provider offering it.
What's the best free WhatsApp chatbot?
None that is genuinely a chatbot. What's free is the WhatsApp Business app, which automates fixed replies but can't hold a conversation. Plenty of platforms advertise a free plan, but it's a trial limited by number of contacts or messages: Meta's per-message cost is charged either way. Before comparing plans, it's worth checking how many people actually message you on WhatsApp today, because in many businesses the volume doesn't justify any subscription at all.
How much does a WhatsApp chatbot cost?
It depends on whether you're answering or chasing. Since 1 July 2025 Meta charges per message: when a customer writes to you, a 24-hour window opens in which replying costs nothing, and outside it you can only send approved templates, with marketing ones always charged. A bot that only answers people who ask spends very little on messages; the fixed cost is the platform subscription.
Do you have to say that people are talking to a bot?
Yes. Article 50 of Regulation (EU) 2024/1689 has applied since 2 August 2026 and requires the person to know they are interacting with an AI system, unless it is obvious. Spain's AESIA warns that this exception is to be read narrowly: the fact that people know chatbots exist is not enough. You solve it by identifying yourself in the first message and offering a clear route to a human.
Shall we see whether your WhatsApp warrants a bot?
We'll tell you whether it's worth it, how much Meta takes and what can be automated in your case. If the answer is no, we'll tell you that too.