selling
Selling a house with Japanese knotweed: can you, and what must you tell the buyer?
Selling a house with Japanese knotweed: the legal position on your land, what the TA6 form asks, how lenders and buyers react and the steps to take first.
- 4 min read
- Last reviewed 4 November 2026
- By Your Property Check team
Key answer
Part 1 of 7
The short answer
General information, not advice. Selling a house with Japanese knotweed is possible. The GOV.UK guidance we read is for England, and we read it on 4 November 2026. The sources we could open set out your legal duties on your own land and how knotweed waste must be handled. They do not set out what every mortgage lender will accept or what treatment costs, so we do not give figures for either.
Part 2 of 7
Your legal position
GOV.UK says "You must stop Japanese knotweed on your land from spreading off your property." It also says you do not legally have to remove knotweed from your land unless it is causing a nuisance, but you can be prosecuted for causing it to spread into the wild. Section 14(2) of the Wildlife and Countryside Act 1981 makes it an offence to plant or otherwise cause to grow in the wild any plant listed in Part II of Schedule 9 of that Act. The legislation page does not list the species, so rely on the GOV.UK guidance for knotweed.
If knotweed is removed, GOV.UK says contaminated material may be classed as controlled waste. If it cannot be dealt with on site, it must go to a landfill or incineration site with the right permit, using a registered waste carrier. GOV.UK also says you must not dispose of it with other surplus soil or sell contaminated soil as topsoil, and that you cannot get a waste licensing exemption for Japanese knotweed. A specialist contractor handles these rules in practice.
Part 3 of 7
What you must tell the buyer
Sellers are asked about their property on the seller's property information form, the TA6. Our guide to the TA6 form lists Japanese knotweed among the environmental matters it covers, alongside flooding and radon. Answer honestly. If you are not sure, say so rather than guess, and tell your conveyancer what you know, including any treatment already carried out. Do not hide a problem, because an inaccurate answer can cause trouble for the sale and afterwards. Ask your solicitor how the form applies to your case.
Part 4 of 7
What buyers and lenders look for
| Situation | What the buyer may ask for | Document that answers it |
|---|---|---|
| Knotweed is present on your land | Where it is, how large it is and who is dealing with it | A specialist survey or report, and your answer on the TA6 form |
| Knotweed has been treated | Proof of what was done and when | Contractor's treatment records and any warranty they gave |
| Knotweed is on a neighbour's land | Whether it affects your boundary | A survey and your answer on the TA6 form |
| The buyer needs a mortgage | Whether the lender will accept the property | The lender's own requirements, which each lender sets |
Our guide to property boundaries can help if the plant sits near a boundary. If the property also has other issues, see our article on subsidence when selling or buying, which uses the same approach of getting a specialist report early.
Part 5 of 7
Who pays for treatment?
The sources we read do not say who must pay. In a sale it is a matter for negotiation: you can treat the plant before you sell, agree a price reduction, or let the buyer deal with it. Whichever route you take, get written quotes and keep records. Because we found no official cost range, we give none.
Part 6 of 7
Management plans and warranties
Specialist firms offer treatment programmes with paperwork, and buyers' lenders may ask to see it. The official pages we could open do not define these documents or set out what a lender requires. Ask your surveyor or the buyer's lender what they need before paying for a plan, so that you do not buy something that does not satisfy them. If the sale involves indemnity cover instead, our guide to indemnity insurance explains how that works, although it is not a cure for knotweed.
Part 7 of 7
Steps to take
- Confirm the plant is Japanese knotweed, using a specialist survey if unsure.
- Stop it spreading, and keep any cuttings or soil away from other land.
- Get quotes from a specialist contractor and keep every record.
- Answer the TA6 form honestly and brief your conveyancer.
- Talk to a mortgage broker or the lender about their requirements.
- Decide whether to treat before selling or agree terms with the buyer.
If you inherited the property, our guide to selling inherited property has more. This page is general information, not advice.
Our take
Get the evidence together before you list
Our view: treat knotweed as a paperwork problem as much as a plant problem. Answer the TA6 honestly, keep contractor records, and ask the buyer's lender what it needs before you pay for any plan. The common mistake is offering reassurance in place of documents.
If you are weighing routes, our sale method comparison compares auction, estate agent and cash buyer on net proceeds and timescale. Our free house valuation gives a value range from Land Registry sold prices. We found no sourced figure for how knotweed affects price, so read any range with that in mind.
Our opinion, drawn from the facts on this page: not advice and not a forecast. We earn from OfferCheck reports and from introducing sellers to cash buyers, so weigh it with that in mind (see our disclosure). We are not authorised or regulated by the FCA.
Questions, answered
Frequently asked questions
Can you sell a house with Japanese knotweed?
Do you have to disclose it, and where?
Will a mortgage lender lend on a house with knotweed?
What is a management plan and an insurance-backed warranty?
Who pays for treatment?
Where this comes from
Sources
- GOV.UK: Prevent Japanese knotweed from spreading
- legislation.gov.uk: Wildlife and Countryside Act 1981, section 14
Last reviewed 4 November 2026 by the Your Property Check team. This page is general information, not legal, tax or financial advice. For your own situation, speak to a conveyancing solicitor or another qualified professional.