A seller completing the TA6 Property Information Form question on Japanese knotweed
Property & mortgages · Guide

Japanese knotweed and the TA6 form

Question 7.8, the duty to answer honestly, and the risk of getting it wrong.

Updated June 2026Sourced from the Environment Agency & RICS
KA
Knotweed Answers editorial
Sourced from official guidance: the Environment Agency, RICS, the Property Care Association (PCA), and UK legislation including the Wildlife & Countryside Act 1981 and the Anti-social Behaviour, Crime and Policing Act 2014.

The short answer

The Law Society’s TA6 Property Information Form asks sellers directly, at question 7.8, whether the property is or has been affected by Japanese knotweed. You must answer honestly. A knowingly false or misleading answer – including a careless ‘No’ – can give the buyer a misrepresentation claim after completion. If you genuinely do not know, the form allows a ‘Not known’ answer, but only where that is truthful.

The TA6 is the standard form your conveyancer uses to tell the buyer about your property. One of its questions is specifically about Japanese knotweed, and how you answer it has real legal consequences. This guide explains exactly what question 7.8 asks, what counts as an honest answer, and what can happen if you get it wrong – so you can disclose properly and protect yourself.

TA6 and knotweed at a glance

What question 7.8 asks

The TA6 Property Information Form, published by the Law Society, includes a dedicated question on Japanese knotweed (question 7.8 in the standard editions). It asks whether the property is, or has been, affected by Japanese knotweed, and – if so – whether there is a management plan and any insurance-backed guarantee. The seller selects an answer and provides supporting documents where relevant. The point of the question is to put the issue squarely on the table before exchange.

What counts as an honest answer

If knotweed has been treated, the honest course is to disclose the history and hand over the management plan and insurance-backed guarantee – which actually helps the sale by reassuring the buyer’s lender.

‘Not known’ is not a safe escape hatch: if it can be shown you did know, answering ‘Not known’ or ‘No’ can still found a misrepresentation claim. Answer to the best of your genuine knowledge.

The risk of getting it wrong

If a seller gives a false or misleading answer on the TA6 and the buyer relies on it, the buyer may bring a claim for misrepresentation after completion, potentially recovering damages reflecting the cost of treatment and any loss in value. Several reported disputes have turned on knotweed answers, which is why conveyancers stress careful, accurate completion. Honest disclosure – coupled with a plan and IBG – is both the safer and the more commercially sensible route. See selling a house with knotweed.

SituationCorrect TA6 approach
Active knotweed on site“Yes” + survey/plan details
Previously treated“Yes” + plan + IBG documents
Genuinely unaware“Not known” (only if true)
Suspect but unconfirmedDisclose the concern; consider a survey

Practical steps

Discuss the answer with your conveyancer, keep records of any survey, treatment and guarantee, and disclose fully. If you are unsure whether what you have is knotweed, our guides on identifying knotweed and getting a survey help you find out before you answer. This is general information, not legal advice – your conveyancer should guide your specific disclosure.

Unsure how to answer the knotweed question?

Get a PCA-accredited survey before completing the TA6. It confirms the position, supports an honest answer and gives the buyer’s lender the documents they need.

Free · no obligation · PCA-accredited surveyors

Frequently asked questions

Do I have to mention Japanese knotweed on the TA6 form?

Yes. Question 7.8 asks directly whether the property is or has been affected. You must answer honestly; a knowingly false or careless answer can expose you to a misrepresentation claim after the sale completes.

Can I just answer ‘Not known’ to be safe?

Only if it is genuinely true. ‘Not known’ is a legitimate answer where you really do not know, but using it to avoid disclosing knowledge you actually have can still found a misrepresentation claim.

What if the knotweed was treated years ago?

You should still answer ‘Yes’ and disclose the history, providing the treatment plan and any insurance-backed guarantee. This is both honest and helpful, because the documents reassure the buyer’s lender.

What can happen if I give a false answer?

The buyer may bring a misrepresentation claim and recover damages, which can reflect treatment costs and any loss in value. Honest disclosure, supported by a plan and IBG, is far safer and usually keeps the sale on track.

Sources & further reading

This guide is general information, not a site-specific survey or legal advice. Japanese knotweed treatment and removal should be assessed by a PCA-accredited specialist before you act.