Can You Use AI-Generated Evidence in a Trademark Dispute?

You can use AI to help you get organised in a trademark dispute, but AI-generated evidence is a different matter. Evidence at the UK Intellectual Property Office (IPO) is a statement of facts from someone who knows them first-hand, signed and checked, and the IPO has shown it will send back material that clearly wasn’t prepared that way. It happened in one of our own recent opposition cases, and it fits a pattern the IPO and the courts have been dealing with for a year.

What happened in our opposition case?

We were acting for a client whose trademark was being infringed, and we were opposing the other side’s trademark application through our trademark opposition service. In this case we were the ones on the front foot. The other party represented themselves, with no professional help, and filed their evidence with the IPO.

The IPO could tell the evidence was completely AI-generated. It told them it would not be accepted and that they would need to redo it. We shared this on The Trademark Helpline’s LinkedIn page because this wasn’t a social media post or a marketing email. It was evidence in a formal legal process, and the people reviewing it spotted straight away that a person hadn’t written it.

Has the IPO dealt with AI in trademark cases before?

Yes, and the published decisions so far have mostly been about AI inventing legal references. Here is the timeline.

• 6 June 2025. The High Court gave judgment in Ayinde v London Borough of Haringey, a ruling on lawyers putting fake, AI-generated case citations before the courts. It warned that AI tools can give answers that sound convincing and are simply wrong.
• 20 June 2025. In Pro Health Solutions Ltd v ProHealth Inc (BL O/0559/25), an appeal from an IPO decision, the Appointed Person (the independent judge who hears appeals from the IPO) dealt with an unrepresented party who had drafted his appeal documents with ChatGPT. They contained made-up quotes and case summaries that didn’t match the real cases. The appeal was dismissed, and the Appointed Person suggested the IPO give parties a clear warning about using AI.
• Later in 2025. A round-up on the IPKat in February 2026 listed further IPO decisions from October and December 2025 where parties cited cases that didn’t exist or didn’t say what was claimed.

Those were about legal arguments. Our case was about the evidence itself, which is arguably more serious, because evidence is what the decision is built on.

Update, September 2026: when we checked the IPO’s list of tribunal practice notices on 25 September 2026, it had not published a specific notice on the use of AI in trademark disputes.

Why doesn’t AI-generated evidence work at the IPO?

Because the IPO’s rules ask for things AI can’t give you. The IPO’s guidance on opposition proceedings explains that evidence is normally a witness statement, and it sets out what that means in plain terms:

• It has to come from personal knowledge. The facts are the witness’s own, not a summary of what a tool thinks is likely.
• It sticks to facts. Legal arguments and opinions go in a separate letter, not in the evidence.
• It is signed and dated, with a statement of truth. That is a signed line confirming the witness believes the contents are true. The guidance says a statement without one will be returned.
• Exhibits are labelled and numbered. Each document gets a reference such as JS1, JS2, and pages in longer exhibits are numbered, or the evidence is sent back.

A statement of truth is a personal promise. If AI has written the facts, filled gaps with guesses or produced generic wording that could apply to any business, the person signing it is putting their name to something they can’t stand behind.

When I put together evidence for an opposition, most of the time goes on the dull, careful part: finding dated invoices, screenshots, adverts and sales figures, checking every date, and making sure each exhibit shows what the statement says it shows. That’s the part that wins or loses a case, and it’s the part AI can’t do for you.

What does it mean if you’re in a trademark dispute?

It means the cost of getting evidence wrong isn’t embarrassment. It’s evidence being returned, time pressure on your deadlines, and a weaker position in front of the person deciding your case. If a dispute ends in a decision against you, costs can follow too, as our write-up of a trademark dispute that turned into a £322,000 costs bill shows.

AI is a genuinely useful tool for organising files or understanding a term. The difference is between using AI to help you work and handing it something serious to do unchecked.

How do you prepare opposition evidence, step by step?

Here is how the process usually runs once a formal opposition has been filed, with the timeframes from the IPO’s guidance.

1. Defence, 2 months. The applicant has two months from being notified of the opposition to file a defence. Both sides can agree a cooling-off period instead, starting at nine months and extendable to a maximum of 18, to try to settle.
2. Evidence timetable, set by the IPO. Once the defence is accepted, the IPO sends both sides a timetable for filing evidence and written submissions. Start gathering on day one, not when the deadline is close.
3. Gather the facts, then write. Collect dated proof first, then write the statement around what the documents actually show.
4. Check every line. Before anyone signs, read each fact against its exhibit. If you’ve used any tool to help draft, check every date, figure and reference against the original.
5. File, then the decision. After the evidence rounds, the IPO invites final submissions or a hearing, and the hearing officer issues a written decision.

If you’re not sure whether you have a case at all, a free trademark search is a quick way to see what’s already on the UK register. A trademark consultation and clearance audit looks wider, at company names, domains, social media and marketplaces, and gives you a risk assessment before a dispute starts.

How can we help with trademark evidence?

A professional doesn’t just fill in forms. We know what credible evidence looks like, how it needs to be presented and what will stand up, and we can’t represent you in court but we can coordinate with our trusted panel of regulated partners where a case needs it. With our trademark representation and protection service, IPO notices come to us, so an evidence deadline isn’t missed while you run your business. If you’re facing an opposition or thinking about bringing one, book a free call, email enquiries@thetrademarkhelpline.com or ring 0161 833 5400. Consultation is free for new clients.

Related questions

• Can I register a trademark myself, or do I need an attorney?
• Someone is already using my business name. What can I do?
• Can someone steal my business name?
• What would it cost me to rebrand if I am forced to change my name?

This article is for information purposes only and does not constitute trademark advice or guidance. Last reviewed 25 September 2026. First shared as a LinkedIn post.

Written by

Laura Spencer

Laura is a Paralegal at The Trademark Helpline. She has worked in the legal sector since 2018, starting in personal injury after completing her degree. At TMH she handles the drafting, review and filing of trademark applications, and is the person clients speak to about queries as an application progresses. She also researches and gathers the evidence behind opposition and infringement cases, and monitors client brands for infringing social accounts. She takes clients through each stage in plain English with a timeframe attached, on the view that people should understand what is happening rather than simply be told it is in hand.