What AI features cost to build in the UK

Published UK pricing for AI features and chatbots, the running costs nobody quotes, and how to tell whether your project needs AI at all.

The App14 team1 min read

The short answer

Published UK pricing puts an SME chatbot at £3,000 to £25,000, and an LLM assistant with retrieval over your own documents at $15,000 to $40,000. The costs people miss are the running ones: API usage, hosting, and a vector database, every month, forever.

What the market charges

What you are buildingPublished rangeAs published
UK SME chatbot£3,000 to £25,000GBP
Rule-based chatbot, no LLM$5,000 to $15,000USD
LLM-powered with retrieval (RAG)$15,000 to $40,000USD
Advanced multi-modal$40,000 to $100,000USD
Enterprise, multi-agent orchestration$100,000 to $300,000+USD
RAG knowledge base added to an existing build£3,000 to £6,000GBP
From the UK App Development Cost Report 2026. Ranges left in the currency each source published.

Regulated sectors, banking and healthcare especially, add 25 to 35% to the baseline.

The running costs

This is where AI differs from ordinary software. A normal feature is built once and costs hosting. An AI feature has a per-use cost forever.

Monthly, ongoing

  • LLM API usageRoughly £50 to £300 a month depending on conversation volume. This scales with success.
  • Cloud hostingCommonly $200 to $1,000 a month for an AI workload.
  • Vector database, if you use retrieval$50 to $500 a month.
  • Maintenance and model changes15 to 20% of build cost annually. Models get deprecated; your prompts and evaluations need revisiting.

Integration costs, itemised

Published add-ons for connecting an AI feature to systems you already run:

IntegrationPublished add-on
CRM (HubSpot, Salesforce)£1,000 to £2,000
E-commerce (Shopify, WooCommerce)£500 to £1,500
Booking system£500 to £1,000
Payment processing£1,000 to £2,000
Custom API or database£1,000 to £3,000

The question to ask before spending any of it

We build AI features when they genuinely do something a query cannot. What we do not do is add a chatbot to a product that needed better navigation.

Common questions

How much does it cost to add AI to an app?

Published UK pricing puts an SME chatbot at £3,000 to £25,000. An LLM-powered assistant with retrieval over your own documents is commonly quoted at $15,000 to $40,000. A RAG knowledge base added to an existing build runs £3,000 to £6,000.

What are the ongoing costs of an AI feature?

LLM API usage of roughly £50 to £300 a month depending on volume, plus cloud hosting and, if you use retrieval, a vector database at $50 to $500 a month. Budget 15 to 20% of the build annually for maintenance and model changes.

Does my app actually need AI?

Usually not. Most requests we get for AI features describe a problem a database query or a well-designed form solves more cheaply and more reliably. AI earns its place when the input is genuinely unstructured language.

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About the author

The App14 team · Design and engineering, Appetite Studio

App14 is the 14-day app sprint run by Appetite Studio, a London-registered design and engineering studio. We design, build, and ship production iOS and Android apps in two weeks, at a published fixed price. Everything we write here comes out of work we have actually delivered: the prices are our real prices, the timelines are our real timelines, and the limits are the ones we genuinely hold to.

Our articles are drafted with AI assistance and reviewed by the App14 team before publication. The prices, timelines, delivery record, and client outcomes described are our own.

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