A house that had rats two years ago and was successfully treated is, in most practical senses, no longer a house with a rat problem. Legally, when it comes to selling that property in England or Wales, the history can still matter, and getting the disclosure wrong is a genuine source of post-sale disputes.
What the TA6 form actually asks
The Law Society’s standard Property Information Form, known as the TA6, is completed by sellers as part of a typical conveyancing process and becomes part of the legal information the buyer relies on when deciding to proceed. It specifically asks about Japanese knotweed by name, and more broadly invites disclosure of defects, disputes and issues affecting the property that a seller is aware of. The form is not an informal questionnaire; once incorporated into the transaction, the answers given carry legal weight, and inaccurate answers can expose a seller to a misrepresentation claim from the buyer after completion.
Why “it’s been treated” is not automatically a clean answer
The general legal principle established through case law and reinforced by professional guidance on completing the TA6 is that a past issue, even one that has been fully and successfully treated, is not the same as a property that never had the issue at all. Guidance specifically addressing Japanese knotweed makes clear that failing to mention treated historic infestations, and not just current ones, can still amount to misrepresentation if a seller answers as though the issue never existed. The safer approach where any past infestation, treatment or ongoing monitoring exists is full disclosure alongside evidence of the treatment carried out, such as a professional treatment certificate or insurance-backed guarantee, rather than treating “it’s sorted now” as grounds to answer as if nothing happened.
What buyers can reasonably ask for
A buyer is entitled to ask specific questions beyond what the TA6 form prompts, and a seller who has had pest problems in the past is generally better served by volunteering documentation, such as invoices from a pest control company, treatment certificates, or any guarantee period still running, than by waiting to be asked directly. This is particularly relevant for issues with a structural dimension, such as woodworm or rodent damage to timber, where a buyer’s surveyor may flag evidence during the standard survey regardless of what the seller discloses, at which point an undisclosed history becomes far more visible than it would have been if raised proactively.
For issues without an obvious ongoing physical trace, such as a wasp nest removed two summers ago, the disclosure bar is generally judged by materiality: whether a reasonable buyer would have wanted to know, given its potential effect on their decision to buy or the price they would offer. When in doubt, disclosing briefly costs little and closes off a much larger legal and financial risk later.
Practical steps before listing a property
If your property has had any significant pest issue, particularly one involving structural elements like timber or affecting a defined area such as a garden boundary, gathering the paperwork before you list is worth doing early rather than scrambling once a buyer’s solicitor raises enquiries. A pest control company that carried out treatment work should be able to reissue a copy of any completion certificate or guarantee documentation if the original has been misplaced, and having this ready alongside your TA6 answers tends to keep a sale moving rather than stalling it.
Where estate agents and conveyancers fit in
Estate agents are separately bound by consumer protection law not to give buyers a false or misleading impression of a property, which is a different but overlapping obligation to the seller’s own TA6 disclosure, and a good agent will usually ask direct questions about pest history at instruction stage precisely to avoid a problem surfacing later in the transaction. Your conveyancing solicitor is a useful resource here too: raising a past pest issue with them before the TA6 is completed lets them advise on the correct wording and any supporting documents to attach, rather than you guessing how much detail is enough. This is generally more useful than trying to resolve the question alone, since solicitors handling residential conveyancing will have seen equivalent disclosure situations many times before and can judge what a reasonable buyer’s solicitor is likely to query.
Buyers, for their part, are entitled to raise specific written enquiries beyond the standard TA6 questions if a survey or general due diligence raises a concern, and a seller who has nothing to hide typically has little to lose by answering these promptly and with documentation rather than treating them as an inconvenience to be managed. Delays caused by late or incomplete disclosure are one of the more common, and most avoidable, reasons a chain slips near exchange, which is a cost that falls on everyone involved, not just the seller.