--- title: "10-Year Knotweed Guarantee | Insurance-Backed Isle of Wight" description: "10-year insurance-backed Japanese Knotweed guarantees, transferable to new owners and accepted by every major UK mortgage lender. Essential for property sales." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://www.isleofwightjapaneseknotweed.com/#organization", "name": "Isle of Wight Japanese Knotweed", "url": "https://www.isleofwightjapaneseknotweed.com/", "areaServed": { "@type": "Place", "name": "Isle of Wight, United Kingdom" }, "knowsAbout": [ "Japanese Knotweed", "Invasive plant removal", "PCA treatment plans", "Insurance-backed guarantees", "RICS knotweed reports" ] }, { "@type": "WebSite", "@id": "https://www.isleofwightjapaneseknotweed.com/#website", "url": "https://www.isleofwightjapaneseknotweed.com/", "name": "Isle of Wight Japanese Knotweed", "publisher": { "@id": "https://www.isleofwightjapaneseknotweed.com/#organization" }, "inLanguage": "en-GB" } ] }, { "@context": "https://schema.org", "@graph": [ { "@type": "Service", "name": "Japanese Knotweed Insurance-Backed Guarantee", "description": "10-year insurance-backed guarantees for Japanese Knotweed treatment on the Isle of Wight. Transferable, accepted by all major UK mortgage lenders, and backed by independent insurers.", "provider": { "@type": "LocalBusiness", "name": "Isle of Wight Japanese Knotweed", "telephone": "+441983509019", "areaServed": "Isle of Wight" }, "serviceType": "Insurance-Backed Guarantee" }, { "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "What is an insurance-backed guarantee for Japanese Knotweed?", "acceptedAnswer": { "@type": "Answer", "text": "An insurance-backed guarantee (IBG) is a 10-year warranty confirming that professional knotweed treatment has been completed. It's backed by an independent insurance company, meaning you're protected even if the treatment company ceases trading. It covers you if the knotweed regrows after treatment." } }, { "@type": "Question", "name": "Do I need an insurance-backed guarantee to get a mortgage?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. All major UK mortgage lenders require an insurance-backed guarantee (or evidence that one will be issued) before approving a mortgage on a property with known Japanese Knotweed. The guarantee must come from a PCA-accredited specialist." } }, { "@type": "Question", "name": "Is a knotweed guarantee transferable to new owners?", "acceptedAnswer": { "@type": "Answer", "text": "Yes. Insurance-backed guarantees are fully transferable to subsequent property owners for the remaining term. This is a key requirement for mortgage lenders and makes affected properties far more attractive to buyers." } }, { "@type": "Question", "name": "How much does a knotweed guarantee cost?", "acceptedAnswer": { "@type": "Answer", "text": "The guarantee is typically included in the overall treatment price. If purchased separately — for example, after completing a treatment programme — it usually costs between £500 and £1,500 depending on the property and infestation history." } } ] } ] } ] --- [](tel:01983509019) [![Isle of Wight Japanese Knotweed](/assets/logo-BKGpI34K.png) Isle of Wight Japanese Knotweed Experts ](/) [Home](/) [About Knotweed](/about-japanese-knotweed) [Treatment](/japanese-knotweed-removal-isle-of-wight) [Property Impact](/japanese-knotweed-property-impact) [Cost Calculator](/japanese-knotweed-removal-cost-calculator) [News](/news) [Get a Quote](/get-quote) [Get Free Quote](/get-quote) Your Protection # 10-Year Insurance-Backed Guarantees An insurance-backed guarantee is the document that makes your property mortgageable again. It confirms professional treatment has been completed and protects you — and future buyers — against knotweed regrowth for a full decade. ## What Is an Insurance-Backed Guarantee? An Insurance-Backed Guarantee (IBG) is a formal warranty confirming that a Japanese Knotweed treatment programme has been completed to professional standards by a PCA-accredited specialist. The guarantee is underwritten by an independent insurance company — separate from the treatment contractor — which means you're protected even if the treatment company ceases trading. The IBG typically runs for 10 years from the date of treatment completion. If the knotweed regrows during this period, the insurer covers the cost of re-treatment at no additional charge to you. The guarantee is fully transferable to subsequent property owners, making it essential for anyone planning to sell their home. In practical terms, the IBG is what transforms a knotweed-affected property from "unmortgageable" to "mortgage-ready." Without one, most lenders simply won't approve finance. With one, the property can be bought, sold, and remortgaged as normal. ## What Your Guarantee Covers Treatment failure protection Full re-treatment at no cost if knotweed regrows Knotweed regrowth coverage Covers any recurrence within the treated area Transferable to new owners Guarantee passes to buyers for the remaining term 10 years from treatment completion Long-term protection exceeding lender requirements Independent insurance backing Underwritten separately from the treatment company All UK mortgage lenders accepted Compliant with CML and individual lender requirements Full documentation provided Complete paperwork for solicitors and conveyancers Ongoing support included Access to the treatment company for queries throughout ### Documentation You Receive IBG certificate Original survey report Complete treatment records Site photographs (before/after) Management plan Completion certificate Insurer contact details Transfer documentation ### Without a Guarantee Properties with known knotweed but no IBG are essentially unmortgageable. Most buyers won't touch them, and those who do will negotiate significant price reductions. A [5-15% drop in value](/japanese-knotweed-property-value) is typical. ## Why an Insurance-Backed Guarantee Is Essential ### Mortgage Requirements All major UK mortgage lenders — including Halifax, Nationwide, HSBC, Barclays, and Santander — require an IBG before approving a mortgage on a property with knotweed. Some will accept evidence that treatment has started with a guarantee pending, but the IBG must ultimately be provided. ### Property Sales & Conveyancing When selling a property with knotweed history, the IBG is the single most important document your buyer's solicitor will request. Without it, the sale is likely to stall or collapse. With it, the transaction can proceed normally — the guarantee simply transfers to the new owner. ### Long-Term Protection Japanese Knotweed rhizomes can remain dormant underground for years before resurfacing. A 10-year guarantee covers this risk. If the plant does regrow — however unlikely with proper treatment — the cost of re-treatment is covered in full by the insurer. ### Company Failure Protection Unlike a simple company warranty, an IBG is backed by an independent insurer. If the treatment company goes out of business during the guarantee period, the insurance company honours the guarantee in full. This is exactly why lenders require independent backing. ## How to Get an Insurance-Backed Guarantee 1 ### Get a professional survey A PCA-accredited specialist surveys your property and creates a treatment plan. 2 ### Complete the treatment programme Follow the agreed plan — herbicide, excavation, or combined approach. 3 ### Pass the monitoring period 2+ years of inspections confirm no regrowth from dormant rhizomes. 4 ### Guarantee issued The 10-year IBG certificate is issued once treatment success is confirmed. The guarantee cost is typically included in the overall [treatment price](/japanese-knotweed-treatment-cost-isle-of-wight). If purchased separately, expect to pay £500-£1,500 depending on the property and infestation history. See our [treatment timeline](/japanese-knotweed-treatment-timeline) for the full step-by-step process. ## Protect Your Property With a Guarantee Get connected with a PCA-accredited specialist on the Isle of Wight who can provide professional treatment with a 10-year insurance-backed guarantee. Free survey, no-obligation quote, and a clear path to peace of mind. 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