Japanese Knotweed and the TA6 Form: What UK sellers must legally disclose

Selling a property with Japanese knotweed? Here's what you must declare—and what happens if you don’t.

In the UK, property sellers are legally required to disclose the presence of Japanese knotweed on the TA6 property information form. This form is part of the standard conveyancing process. Failing to answer truthfully—or omitting the information—can lead to legal action and compensation claims from buyers, covering treatment costs and lost property value.

As a mortgage adviser, it’s crucial to alert clients to this early. If a seller confirms current or past knotweed issues, the buyer should request a professional treatment plan and a 10-year insurance-backed guarantee. This not only reassures lenders but protects all parties involved.

If knotweed is discovered after completion and wasn’t declared, the buyer may have legal recourse—but it's a stressful, avoidable situation. This includes even historic infestations that have been treated, as lenders and surveyors may still consider the property at risk. Promoting transparency and due diligence helps prevent disputes and ensures a smoother mortgage process.

Thinking of buying or remortgaging a home with Japanese Knotweed? Speak to a specialist mortgage professional experienced with knotweed.

Your home may be repossessed if you do not keep up repayments on your mortgage.

You may have to pay an early repayment charge to your existing lender if you remortgage.