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What does a WhatsApp assistant cost to run in the UK?

For a UK estate agent or dental practice, a WhatsApp assistant costs two things to run: Meta’s fee per delivered message and the model that writes the replies. From 1 October 2026 Meta charges £0.0159 (US$0.022) for each reply after the first 1,000 a month on each WhatsApp number, and in our own measurement the model added about US$0.36 per 1,000 replies.

So if an assistant sends 500 replies in a month, Meta charges nothing and the model costs about US$0.18. If it sends 2,000 replies and 300 appointment or viewing reminders, Meta charges about £20.67 (£15.90 for the 1,000 replies over the free tier, £4.77 for the reminders) and the model about US$0.72. What a builder or provider charges on top is separate, and this guide does not cover it.

Updated Oct 6, 2026

How it works

  1. Messages people send are free

    Meta charges only for messages the business delivers. Every enquiry a renter, buyer or patient sends costs nothing.

  2. Replies inside 24 hours: the first 1,000 a month are free

    A reply within 24 hours of the person’s last message is a service message. From 1 October 2026 each WhatsApp number gets 1,000 free a month; after that, £0.0159 each for people with a UK number.

  3. Reminders and confirmations are templates

    A reminder sent a day before a viewing or appointment goes out as an approved template (a utility message): £0.0159 each. It is written once, so the model costs nothing for it.

  4. Marketing costs almost three times more

    A marketing template is £0.0458 per message to a UK number. An assistant that answers enquiries does not need to send any.

  5. The model is paid per token

    A token is a small piece of a word. For each reply the model reads the business’s facts and the conversation, then writes a short answer; most of what it reads repeats, and repeated text is billed at a tenth of the price or less.

What it costs to run

Meta’s prices are for people with a UK number, from its rate cards in pounds and in dollars; which one you pay depends on your WhatsApp Business account’s currency. The model prices are list prices: the model our previews run on, and Claude Haiku 4.5 for comparison. The website chat has no Meta fee at all.

ItemList priceSource
WhatsApp reply inside the 24-hour window (service message), UK numberFree for the first 1,000 a month on each number from 1 Oct 2026, then £0.0159 (US$0.022) per delivered messageMeta for Developers, WhatsApp rate cards in GBP and USD effective 1 Oct 2026, United Kingdom (Pricing on the WhatsApp Business Platform)Read on Oct 6, 2026
Reminder or confirmation template (utility message), UK number£0.0159 (US$0.022) per delivered messageMeta for Developers, WhatsApp rate cards in GBP and USD effective 1 Oct 2026, United Kingdom (Pricing on the WhatsApp Business Platform)Read on Oct 6, 2026
Marketing template, UK number£0.0458 (US$0.0635) per delivered messageMeta for Developers, WhatsApp rate cards in GBP and USD effective 1 Oct 2026, United Kingdom (Pricing on the WhatsApp Business Platform)Read on Oct 6, 2026
Messages within 72 hours of a click-to-WhatsApp adFree (the free entry point window)Meta for Developers, WhatsApp rate cards in GBP and USD effective 1 Oct 2026, United Kingdom (Pricing on the WhatsApp Business Platform)Read on Oct 6, 2026
Model: GPT-6 Luna (OpenAI), the model our previews run onUS$0.10 per million input tokens, US$0.01 per million cached input tokens, US$0.50 per million output tokensVercel AI Gateway, model list and prices (openai/gpt-6-luna)Read on Oct 6, 2026
Model: Claude Haiku 4.5 (Anthropic), for comparisonUS$1 per million input tokens, US$5 per million output tokensAnthropic, Claude API Docs, PricingRead on Sep 28, 2026

Third-party list prices, read on the date shown. They are not Betterlane prices.

What we learned building it

Our own measurement, without any customer: 945 replies that our previews for estate agencies and clinics gave to our own test messages, 4–6 October 2026, on GPT-6 Luna through Vercel’s AI Gateway, which billed each call.

About US$0.36 per 1,000 replies
The gateway billed an average of US$0.00036 a reply. Our test conversations were short (two replies on average), so a longer real conversation costs more per conversation, not per reply.
Most of what the model reads is repeated
Each reply read about 5,200 tokens, mostly the business’s facts, and wrote about 110. 58% of what it read was cached, which is why the cost per reply stays this low. At Claude Haiku 4.5’s list price, the same replies would cost roughly ten times as much.

When it is not worth it

  • If fewer than a few dozen enquiries a month arrive on WhatsApp, the free WhatsApp Business app and an away message may be enough: the fees here are small, but setting up the API is not.
  • If your enquiries come mostly through your website, a website chat has no Meta fee; the model is its only running cost.

Questions

Is the WhatsApp Business app free?

Yes. The app on a phone has no per-message fee. The fees in this guide apply to the WhatsApp Business Platform, the API that an assistant uses to answer on the business’s number.

Do I pay in pounds or dollars?

Meta publishes the same rates in pounds and in dollars, among other currencies. Which one you are billed in depends on the currency of your WhatsApp Business account.

Does a WhatsApp provider add its own fee?

Often. If you connect through a Business Solution Provider instead of Meta’s Cloud API directly, the provider may add a monthly or per-message fee on top of Meta’s. Check its price list.

What does Betterlane charge?

This guide covers only third-party costs. What we charge is agreed on a call before anything is built, and the first flow is built free in ten days.

Sources

Want to see what an assistant would answer on your WhatsApp?

See the service: AI automation agency in the UKLet’s talk

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