The TA6 property information form asks sellers directly whether the property is affected by Japanese knotweed. Answering it honestly, with a management plan to hand, is the best way to keep a sale on track.
What lenders want
Most lenders will lend on a property with knotweed if there is a professional treatment plan in place, often with an insurance-backed guarantee that transfers to the buyer.
Timing
Starting treatment before you market the property means you can show progress. If the sale is urgent, excavation is quicker but costs more.