Ask five companies what an AI chatbot costs in the UK and you'll get five answers that differ by a factor of a thousand. One quotes £15 a month. Another quotes £40,000. Both are technically telling the truth — they're just describing completely different things and hoping you won't ask.
We build chatbots for UK small businesses, so here's the version with the pricing left in.
The short answer
In the UK in 2026, an AI chatbot costs one of three things:
- Off-the-shelf widget: £15–£100 per month. A subscription tool like Tidio or Chatbase you set up yourself. Watch the fine print — the AI features usually cost extra on top of the advertised price.
- Productised build: £2,000–£5,000 one-off. A chatbot built for you and trained on your own documents — your price lists, your policies, your services — so it answers like someone who actually works there.
- Fully custom build: £4,000–£15,000+ one-off. Website and WhatsApp together, wired into your booking system or CRM, so it doesn't just answer questions — it books the job and logs the lead.
Whichever tier you pick, budget £80–£250 a month in running costs after launch for the built options. Anyone quoting a build price with no mention of running costs is leaving something out.
Why quotes range from £15 a month to £40,000
The spread is real. Tidio's cheapest paid plan is about £25 a month, while UK dev-shop pricing guides quote £15,000–£30,000+ for an enterprise-grade build on internal data (Softomate Solutions' 2026 UK buyers guide), and some agencies put production-grade enterprise systems at £60,000–£250,000 (QuantumXL's 2026 cost guide). Nobody's lying. They're pricing three different products that all get called "a chatbot".
The £0 option first: is ChatGPT enough?
Worth answering before you spend anything. ChatGPT is a tool you use; a chatbot is a tool your customers use. ChatGPT doesn't know your prices, can't sit on your website, can't take a booking at 11pm, and will cheerfully make up an answer about your returns policy because it's never read it.
If your budget is genuinely zero, use ChatGPT internally — drafting replies to enquiries, summarising long email threads. That's free value. But it is not a customer-facing chatbot, and no amount of prompting turns it into one.
Off-the-shelf widgets — cheap, generic, and why customers hate most of them
This is the £15–£100/month tier, and the advertised price is rarely the real price. Tidio's base plans run $29–$59 a month (roughly £23–£47), but its Lyro AI agent is a separate add-on starting at $39 a month for just 50 AI conversations — and on the free plan those 50 conversations are a one-time allowance, not monthly (Tidio's pricing page; Chatarmin's 2026 teardown). Chatbase runs from $32 a month on annual billing to $400 for the Pro tier, metered in message credits (Chatbase's pricing page). Intercom's Fin charges $0.99 — call it 80p — per resolved conversation, with a 50-resolution monthly minimum that puts the real floor near $49.50 (Intercom's pricing page).
What you get for this money is a widget with either scripted button-flows or a generic AI trained on whatever you manage to paste in (Chatbase's $32 tier caps training data at 10MB). And this is why customers hate most of them: they either loop — "Sorry, I didn't understand. Here are four buttons" — or they confidently improvise answers about your business that your business never agreed to.
Where they earn their keep: as a cheap experiment. If you want to find out whether your website visitors will even use a chat window before spending real money, £25 a month answers that question fast. That's a legitimate use, and we'd rather you did it than skipped straight to a £10k build on a hunch.
Productised builds — trained on your documents, your prices, your policies
This is the tier most UK small businesses actually need, and it's the core of our chatbot development service: £2,000–£5,000, fixed scope, typically live within a few weeks.
The difference isn't a fancier widget. It's that the bot has read your stuff. Your price list, your service pages, your delivery terms, your opening hours, the PDF you send every new customer. When someone asks "how much is a boiler service in Croydon?", it answers from your actual price list — not from a vague statistical memory of what boiler services cost.
The honest trade-off: at this tier the bot answers brilliantly but doesn't do much. It can't check your live calendar or write into your CRM. It captures the lead and hands over. For a lot of businesses, that's 80% of the value at 30% of the custom price.
Fully custom — WhatsApp + website, wired into your booking and CRM systems
£4,000–£15,000+, depending on what it touches. This is where the bot stops being an FAQ and starts being a receptionist: it answers on your website and on WhatsApp, checks live availability, books the appointment, writes the enquiry into your CRM with the full transcript, and hands anything weird straight to a human.
What pushes the price up is integrations, not intelligence. Each system the bot has to read from or write to — booking platform, CRM, stock system, payment link — is real engineering work with real edge cases. Two integrations and one channel sits near the bottom of the range; five integrations, two channels and compliance requirements sits near the top.
When is £15,000 justified? When the bot is replacing a measurable chunk of a person's job or capturing revenue you're provably losing — missed calls, out-of-hours enquiries, a sales inbox nobody answers until Monday. When it isn't: when you haven't tested that customers want to chat with you at all. Start a tier down.
The bit that changes everything: a bot that only answers from your documents
The technique behind tiers two and three is called retrieval-augmented generation — RAG. Ignore the name; here's what actually happens:
- Your documents — price lists, policies, service pages, that battered FAQ Word doc — get indexed into a searchable knowledge base.
- A customer asks a question.
- The system fetches only the passages relevant to that question.
- The AI writes its answer using only those passages — not its general knowledge of the internet.
- If nothing relevant exists, it says so and offers a human, instead of guessing.
Three things fall out of this that matter commercially. First, the bot stops making things up about your business, because it's not allowed to answer from anywhere except your documents. Second, updates are instant: change the price list, re-index, and the bot's answers change the same day — no retraining, no developer. Third, answers can cite their source, so you can audit exactly why the bot said what it said.
One more thing worth knowing: your documents don't have to be shipped off to someone else's chat platform to make this work. For businesses with genuinely sensitive data — client files, medical info, commercial pricing — we build private LLM setups where the model and the data both stay in-house. It costs more, but "our data never leaves the building" is sometimes the whole requirement.
WhatsApp chatbots in the UK — API approval, per-message costs, GDPR
Yes, you can put an AI chatbot on WhatsApp — but not through the free WhatsApp Business app on your phone. Bots need the WhatsApp Business Platform (the API), which means verifying your business in Meta Business Manager and getting a display name approved, either directly through Meta's Cloud API or via a Business Solution Provider like Twilio. Verification typically takes days, not months, and the approval itself costs nothing.
The costs come per message, and the structure changed on 1 July 2025, when Meta scrapped per-conversation pricing for per-delivered-message pricing. Current UK rates are roughly 6p per marketing message and 2p per utility message (order updates, booking confirmations), per SleekFlow's 2026 UK rate table. If you go through a provider like Twilio, add a markup of roughly $0.005–$0.010 per message on top (Twilio's WhatsApp pricing page).
Here's the detail that most pricing guides bury: when a customer messages you first, a 24-hour customer service window opens, and everything you send back inside it is free. A support or enquiry bot lives almost entirely inside that window. So a WhatsApp bot that answers inbound questions costs approximately nothing in message fees — a thousand inbound customer chats a month is £0 to Meta. What costs money is outbound marketing: 5,000 promotional messages runs about £300 a month before provider markup.
On GDPR: replying to people who message you is straightforward. Sending outbound marketing messages needs opt-in consent under UK GDPR and PECR — the same rules as marketing emails and texts — so collect consent properly and keep records. And whichever platform handles your messages, make sure there's a data processing agreement in place and your privacy notice mentions it. None of this is exotic; it just needs doing before launch, not after a complaint.
Running costs: what you'll pay per month after launch
The build price is not the whole price. For tiers two and three, budget £80–£250 a month, made up of:
- AI model usage — the per-message cost of the model generating answers. For typical small-business volumes, £10–£50 a month.
- Hosting — £5–£30 a month for the infrastructure the bot runs on.
- Channel fees — WhatsApp message costs if you're on WhatsApp (often near £0 for inbound-only, as above).
- Care and maintenance — the biggest slice, and the one that matters. Someone needs to review the conversations the bot fumbled, update the knowledge base when your prices or policies change, and keep the underlying models current.
Skip that last line and the bot doesn't break — it does something worse. It keeps confidently answering with last year's prices and a discontinued service, and you find out from an annoyed customer. A stale chatbot is a liability with a chat window.
Is it worth it? (and when a bot is the wrong call)
One of our chatbot clients told us it "doubled my revenue." The mechanism behind results like that is usually boring: enquiries that arrive out of hours and silently die start getting answered instead. A bot doesn't create demand — it stops existing demand leaking away.
That's the honest maths to run on your own business. Count the enquiries that currently go unanswered — evenings, weekends, the phone ringing while you're on a job — and put a value on them. If missed enquiries are worth more than a few hundred pounds a month, a £2,000–£5,000 build pays for itself embarrassingly fast. If they're not, don't build one.
And when is a bot the wrong call? Three cases where we'd tell you not to build one:
- You don't have the traffic. If your website gets a handful of visitors a week, a chatbot optimises a queue that doesn't exist. Fix marketing first.
- Your conversations are high-stakes or emotional. Complaints, sensitive negotiations, distressed customers — a bot fielding these makes things worse. Humans first, bot for the routine stuff.
- Your real problem is admin, not enquiries. If you're drowning in invoicing, scheduling and copy-paste between systems, that's a workflow automation job, not a chatbot job — different tool, often better ROI.
FAQ
How much does an AI chatbot cost in the UK?
£15–£100 a month for an off-the-shelf widget you configure yourself; £2,000–£5,000 one-off for a build trained on your own documents; £4,000–£15,000+ for a fully custom bot across website and WhatsApp with booking/CRM integrations. Built options add £80–£250 a month in running costs.
Can an AI chatbot answer questions from my own documents and price lists?
Yes — this is exactly what a RAG-based build does. Your documents are indexed, and the bot answers only from them, so it quotes your actual prices and policies rather than guessing. Update the documents and the answers update with them.
Can I get an AI chatbot on WhatsApp for my business?
Yes, via the WhatsApp Business Platform (API), which requires Meta business verification — typically days, not months. Replies to inbound customer messages within the 24-hour service window are free; outbound costs roughly 2p per utility message and 6p per marketing message in the UK, and marketing messages need opt-in consent under UK GDPR/PECR.
Is ChatGPT enough, or do I need something custom built?
ChatGPT is a tool you use; a chatbot is a tool your customers use. ChatGPT doesn't know your prices, can't sit on your website or WhatsApp, and can't take bookings — use it free for internal drafting, but customer-facing work needs a bot trained on your own data.
What does an AI chatbot cost to run each month?
Budget £80–£250 a month: model usage (£10–£50), hosting (£5–£30), any WhatsApp fees, and — the important bit — ongoing care to keep the knowledge base current so the bot never quotes last year's prices.
How long does an AI chatbot take to build?
A productised build trained on your documents typically ships in a few weeks. A custom multi-channel build with booking and CRM integrations usually runs a couple of months, depending on how many systems it connects to.
Not sure which tier you need?
That's the most common starting point, honestly — in our experience, most businesses that come to us asking about chatbots need tier two, and a few need no bot at all. Our free AI audit looks at where your enquiries actually leak, tells you which tier fits (including "none — fix this other thing first"), and puts real numbers on it. No slide deck, no obligation, no chatbot trying to sell you a chatbot.