Last updated 6 November 2026

Terms and conditions

These terms apply when you use our free mansion tax checker or order one of our paid services. Please read them before you order. If anything is unclear, email us at info@challengemansiontax.co.uk.

1. Who we are

Challenge Mansion Tax is run by Simon Dredzen, trading as Challenge Mansion Tax, 3rd Floor, 45 Albemarle Street, Mayfair, London W1S 4JL. Email: info@challengemansiontax.co.uk. We are an independent service and are not connected with HMRC, the Valuation Office Agency or any local council.

2. Our services

• Free: the mansion tax checker, the emailed report, the personalised preview and a free consultation. These give general information only.
• Property Value Evidence Pack: we prepare an evidence file about your home's value at April 2026 built from completed sales, personally reviewed by our property expert. The service is complete when we deliver your pack.
• Free follow-up: when draft valuations are published, expected in autumn 2027, we'll compare your home's draft valuation with your Property Value Evidence Pack and tell you whether a challenge merits consideration. To ask for it, reply to the email your pack came with, or email info@challengemansiontax.co.uk. This is a free extra we offer to customers, not part of the paid service.
• Appeals Service: when draft valuations are published and the challenge window opens, we prepare and submit your challenge to the Valuation Office within the deadline and handle its questions and correspondence. It does not include an appeal to the Valuation Tribunal, including attending any hearing, which we can quote for separately, or the fees of any RICS-registered valuer or other expert, which you pay only if you agree to instruct them.

What each service includes, and its price, is set out on our Services and fees Mansion tax appeals page. That page forms part of these terms.

3. What our services are not, and changes to the mansion tax

Our estimates and Property Value Evidence Packs are evidence reviews built from public sales data. They are not a RICS valuation, an official Valuation Office assessment, or tax, legal or financial advice. Where the sums justify a formal valuation from a RICS-registered valuer, we'll recommend one, at cost and only with your agreement.

The mansion tax (the High Value Council Tax Surcharge) is still being put in place. Its rules, valuation date, bands and challenge process may change, and we'll follow the rules as they apply when we do the work. If the surcharge is abandoned before we submit a challenge, there is nothing to pay for the Appeals Service, because it is paid only when we submit.

4. Purpose and reliance

Your Property Value Evidence Pack, including its Indicative Value, is prepared solely to help you consider your liability for the High Value Council Tax Surcharge. It must not be relied on for any other purpose, including as a valuation, for selling, buying or letting a property, for mortgages, borrowing or lending, for insurance, or for any other tax. For any other purpose, instruct a RICS-registered valuer.

We prepare it with reasonable care and skill. But because the Indicative Value is an indicative assessment, reached without any inspection or viewing of the property, we can't guarantee its accuracy, and your home's actual market value may vary significantly. We're not responsible for any use of the pack other than considering your High Value Council Tax Surcharge liability. This doesn't affect your legal rights as a consumer.

5. No guaranteed outcome

We prepare evidence to support a challenge. Whether a band changes is decided by the Valuation Office and, on appeal, the Valuation Tribunal, so we can't guarantee that a challenge will succeed or that you will save any money. If our review finds the evidence doesn't support a challenge, we'll tell you.

6. Ordering and payment

You place an order through the order form on our website. Before you submit it, you are shown the service, its total price, how to pay and these terms. Submitting the order form does not commit you to pay: you commit to pay when you complete payment on the payment page that follows. Your order is accepted when we confirm it by email. Our confirmation includes these terms, the record of your request for us to start work, and a cancellation form.

• The Property Value Evidence Pack is paid in advance. We will normally deliver your pack within 7 calendar days of receiving both your payment and all the information we reasonably need to prepare it, provided you have asked us to start work during the cancellation period (see section 9).
• The Appeals Service is paid when we submit your challenge.
• Prices are fixed and include VAT where it applies. We don't charge a success fee or a percentage of your savings.
• Everything you paid for the Property Value Evidence Pack comes off the Appeals Service if you go ahead.
• Introductory prices apply only to orders placed by the date shown.

7. What we need from you

To prepare your pack we need accurate information about your home, such as its address, floor area, floor level, lease, condition and any works, and sometimes photos or documents. You're responsible for making sure the information you give us is accurate and complete. Our work relies on it: if it's inaccurate or incomplete, our findings and the Indicative Value may be inaccurate too, and we can't be responsible for that. We remain responsible for using reasonable care and skill in our own research and analysis.

We'll ask for anything we need when we confirm your order. Our 7-day delivery time starts once we have it.

8. Voluntary refund if your home is far from a band threshold

We always prepare and deliver your Property Value Evidence Pack. If the Indicative Value in your pack is more than 25% away from the nearest band threshold (£2m, £2.5m, £3.5m or £5m), a challenge is unlikely to move your home into a different band. In that case you can ask for a refund of what you paid, less a £50 administration fee, by emailing us within 30 days of receiving your pack.

We work out the percentage as the difference between the Indicative Value and each threshold, divided by that threshold, and use the smallest result. For example, a home with an Indicative Value of about £6.5m is 30% above the £5m threshold, and one of about £1.4m is 30% below £2m.

This refund is a voluntary goodwill policy. It is in addition to, and does not replace or restrict, your right to cancel in section 9 or your rights if our service is not provided with reasonable care and skill. The £50 administration fee applies only to refunds under this policy, never to refunds you are entitled to by law.

9. Your right to cancel

If you are a consumer, you normally have the right to cancel your order within 14 days after the day on which we accept it, without giving a reason.

You can cancel by emailing info@challengemansiontax.co.uk, by writing to us at the address in section 1, or by sending us any other clear statement of your decision. You can use the model cancellation form below, but you don't have to.

Starting work during the cancellation period: we will not start your paid service during the 14-day cancellation period unless you expressly ask us to. You do this with the tick box on the order form.

• If you cancel before work begins, we refund you in full.
• If you cancel after work begins but before the service is fully provided, we may charge a proportionate amount for the work already done, and refund the rest.
• If the service has been fully provided after you asked us to start and acknowledged that you would lose your right to cancel once it was, your right to cancel that service ends. The Property Value Evidence Pack is fully provided when we deliver it.

We make any refund due without undue delay and within 14 days of being told of your cancellation, using your original payment method unless you agree otherwise. This doesn't affect your rights if our service is not provided with reasonable care and skill.

10. If something goes wrong, and our responsibility

We provide our services with reasonable care and skill. If you believe we've made an error, please contact us. We'll look into it and, where appropriate, correct it without charge.

Our evidence reviews provide indicative assessments, not formal property valuations. We can't guarantee that the Valuation Office, a council or a tribunal will accept our conclusions, or that your High Value Council Tax Surcharge liability will be reduced.

We're responsible for losses you suffer that are a foreseeable result of our breaking these terms or failing to use reasonable care and skill, but not for losses that were not foreseeable. We're not responsible for decisions made independently by public authorities, or for losses caused by inaccurate or incomplete information you gave us, provided we used reasonable care and skill.

Nothing in these terms excludes or restricts your legal rights as a consumer, or any liability that can't lawfully be excluded or restricted, including liability for fraud or for death or personal injury caused by negligence.

11. Using our materials

Your Property Value Evidence Pack is for you to use for your own home, for the purpose in section 4. You can share it with your advisers, a valuer, the Valuation Office, your council or a tribunal for that purpose. Please don't share the sample pack or republish our reports. Sales data comes from HM Land Registry and energy performance certificates, under their licences.

12. Your information

How we use your personal information is explained in our privacy policy.

13. Complaints

Email info@challengemansiontax.co.uk or write to us at the address in section 1. We'll reply within 14 days.

14. Changes and law

We may update these terms. The terms that apply to your order are the ones on this page when you placed it. These terms are governed by the law of England and Wales. If you live elsewhere in the UK, you can bring proceedings in your local courts, and nothing in these terms takes away any mandatory consumer protection of the law where you live.

Model cancellation form

Complete and return this form only if you wish to cancel the contract. Copy it into an email to info@challengemansiontax.co.uk, or post it to the address in section 1.