AI-Built Website Liability Under UK Law

Your developer built your site in three days using Cursor and Claude. Six months later the ICO sends a letter about cookies firing before consent. The developer is asking ChatGPT whether you can blame the AI. The short answer is no, and the UK story is slightly different from the EU one.

The short answer: you do

Article 4(7) of the UK GDPR, retained from the EU GDPR by the Data Protection Act 2018, defines the controller as whoever determines the purposes and means of processing personal data. The site operator decides what cookies fire, what analytics load, what the contact form does and where the data goes. The AI tool that wrote the code is neither a controller nor a processor for the site's visitors. It processed the developer's prompt, which is a separate transaction with a separate counterparty.

The ICO cares about who runs the website. That is whoever Companies House names, whoever the privacy notice identifies, whoever takes payments. The ICO does not need to know which tool wrote the cookie banner and will not ask.

Why the AI tool is not on the hook

Three structural facts keep the AI vendor out of the chain.

First, the major AI coding tools' terms of service push responsibility for outputs onto the user. The pattern is consistent across OpenAI, Anthropic, GitHub Copilot, Cursor and Lovable as of May 2026. Outputs are "as is". The user verifies them. The user indemnifies the provider against third-party claims arising from outputs. When the developer accepts the code Cursor suggested, the legal weight of that decision lands on the developer, not on Cursor.

Second, the AI provider is not a controller or a processor for the site's visitors. The ICO's own guidance on AI and data protection, last updated in 2025, treats the deployer of an AI system as carrying its own accountability obligations even where the model was developed by someone else. The deployer is the site operator, on the operator's domain, processing the operator's data subjects.

Third, neither the EU AI Liability Directive (which was withdrawn anyway in October 2025) nor the EU Product Liability Directive 2024/2853 applies in the UK. The EU PLD was adopted after Brexit and the UK is not bound by it. The UK regime stays under the Consumer Protection Act 1987 (Part I) and the Sale of Goods Act 1979 family, neither of which expressly treats general-purpose software or AI models as "products" the way EU law now does.

What about the developer that used the AI?

The agency-client liability chain pre-dates AI by decades. The same logic that applies to a developer who used unlicensed images applies to one who used an AI assistant to generate code. How web designer liability works in the UK covers the underlying framework: implied terms of reasonable skill and care under section 13 of the Supply of Goods and Services Act 1982, and the operator's separate exposure to the rights holder or the ICO.

The AI layer adds one structural fact. The developer's contract with the AI provider almost always indemnifies the provider, not the developer or its client. The operator never had a contract with the AI vendor. The developer did. The developer promised the vendor that they, the developer, would carry the risk of using the outputs. That promise does not flow through to the operator, and it does not open a route to the AI provider's legal team.

The contract between operator and developer is the only document that matters when the operator wants to push the cost back. If the contract is silent on compliance warranties, AI-use disclosure and indemnification, the operator is negotiating from a weak position.

What is changing in the UK in 2026

The Data (Use and Access) Act 2025 received Royal Assent on 19 June 2025. Section 138 obliges the government to publish a report on AI and copyright by 18 March 2026. That report is the point at which UK obligations on AI use in commercial settings may start to harden. Until then, AI use by your developer does not create a new layer of UK regulatory obligation on top of UK GDPR, PECR and the Equality Act 2010.

Getty Images v Stability AI [2025] EWHC 2863 (Ch), handed down 4 November 2025, narrowed the question of whether training a model on copyrighted images is itself an infringing act under English law. That judgment is about the model, not about the website that consumes its outputs. It does not change who is liable when an AI-built site fails UK GDPR or PECR.

The EU Product Liability Directive 2024/2853, with its strict-liability route against software producers, does not apply in the UK. A UK website operator harmed by a defective AI coding tool cannot use it as a claim path. UK product-liability law under the Consumer Protection Act 1987 has not been updated to treat general-purpose AI tools as "products" in the same expansive way. As of May 2026 the practical position is: the operator pays, the operator pursues the developer in contract and the developer's options against the AI vendor are limited to what their own AI vendor contract says.

Three practical scenarios

The AI-built cookie banner has no working reject-all button. The ICO enforces against the operator under the Privacy and Electronic Communications Regulations 2003 (PECR) regulation 6 and UK GDPR Article 4(11). The developer may be liable to the operator under section 13 SGSA 1982 implied terms, but only if your contract said the deliverable would meet PECR. Whether your site needs a cookie banner is the cheapest question to answer correctly before launch.

The AI-built contact form ships data to a US service without a UK International Data Transfer Agreement (IDTA) or addendum. That is a UK GDPR Chapter V breach, enforced against the operator. The developer may have used a default Cursor or Claude pattern that hard-coded the third party. The developer owes a fix and, if the contract is good, any fine that follows.

The AI-generated alt text is wrong or missing on most images. The Equality Act 2010 imposes a duty to make reasonable adjustments on service providers operating UK-facing websites. Tribunal awards in disability discrimination cases follow the Equality Act Vento bands, and the rule applies regardless of who or what wrote the alt text. AI-generated alt text that hallucinates is worse than no alt text in that context, because a screen reader reads it confidently to a disabled visitor.

How to push the risk back to your developer

The contract is the only lever. Before signing, insist on:

• An indemnification clause that names the operator and covers third-party claims arising from non-compliance of the delivered site.
• A compliance warranty: the developer warrants the site meets UK GDPR, PECR, the Equality Act 2010 and applicable consumer law at delivery.
• A disclose-AI-use clause: the developer lists which AI tools generated which deliverables. Useful for your own DUAA reporting if rules harden after March 2026 and useful for the EU AI Act Article 50 transparency obligations from 2 August 2026 if you also serve EU residents. <!-- TODO: replace with /uk/en/guides/eu-ai-act-for-website-owners when cluster #4 publishes -->
• A right-to-scan clause: the operator may run a compliance scan before sign-off and any criticals must be fixed.
• A post-delivery support window: the developer fixes compliance defects found within the first 90 days at their own cost.

A developer that resists these clauses is signalling they are not confident in what they are delivering.

What to check on your own site today

Five things you can verify without a developer. Two minutes per check.

1. The cookie banner has a reject-all button that is as visible as accept-all and does not pre-tick anything.
2. Analytics and marketing scripts load only after consent.
3. The privacy notice is in your actual company name and Companies House number, not a placeholder like [Your Company] left over from an AI template.
4. Alt texts are present on key product images and describe the image rather than just saying "image of".
5. A keyboard-only visitor can reach the main pages and the checkout without a mouse.

If any of these are uncertain, our free compliance scan checks UK GDPR, cookies, accessibility and image rights. It will not tell you whether your AI tools are legal. It will tell you whether the site they helped build is.

Common Questions

If my developer used Lovable, Bolt or v0 to build my UK site, am I liable for compliance issues?

Yes. Under Article 4(7) UK GDPR you are the controller, regardless of whether the code was written by a human or an AI. The ICO enforces against the controller, not the tool.

Can I sue OpenAI or Anthropic if their tool produced non-compliant code in the UK?

Almost never. You have no contract with them as an end user of a tool your developer picked. Their terms push responsibility for outputs onto the user. The EU Product Liability Directive 2024/2853 does not apply in the UK post-Brexit. UK product liability under the Consumer Protection Act 1987 has not been updated to expressly include software.

Does the EU AI Act bind UK websites?

Only if they market to or process EU residents. For UK-only operations, the AI Act does not bind you. The UK government's response to its 2025 AI copyright consultation, due 18 March 2026 under the Data (Use and Access) Act 2025, may shape UK rules. Until then UK obligations come from UK GDPR, PECR, the Equality Act 2010 and existing IP law.

What about Getty v Stability AI? Does that affect my liability?

Not directly. The 4 November 2025 judgment in [2025] EWHC 2863 (Ch) was about whether the model itself infringed Getty's copyright. It is about AI providers and rights holders, not about whether a website owner is liable for what AI tools generated on the operator's site.

My developer disclaims AI use in their contract. Does that protect me?

Not from the ICO. The regulator looks at the controller, which is you. A disclaimer between you and your developer only affects who reimburses whom internally. Replace any AI-use disclaimer with a compliance warranty: the developer warrants the delivered site meets UK GDPR, PECR and the Equality Act at handover.

Related reading

If you want to go further on the questions this article touched on:

• The agency-client liability chain pre-dates AI. How web designer liability works in the UK covers the framework before the AI layer.
• Why the EU PLD does not save UK operators. The UK reform schedule depends on the March 2026 government response. <!-- TODO: replace with /uk/en/guides/product-liability-directive-uk when published -->
• AI Act transparency obligations from 2 August 2026 (relevant only if you also serve EU residents). <!-- TODO: replace with /uk/en/guides/eu-ai-act-for-website-owners when published -->
• The cookie banner is where most AI-built sites fail first. Whether your site needs a cookie banner is the cheapest question to answer correctly.
• The fine ranges that make this question worth asking. UK GDPR fines from the ICO explains the real exposure.

This article is technical analysis, not legal advice. The author is not your solicitor and is not your registered controller. For a binding view, talk to one of those.