Who we are
Mansion Taxes is a trading name of SGS Ltd, a tax consultancy based in Guernsey. SGS works across a family of specialist tax services, and Mansion Taxes is the one focused on the surcharge.
Reviews are carried out with a qualified tax adviser and a property surveyor. The tax adviser deals with liability, ownership structures and deferral. The surveyor deals with the facts of the home and the 2026 evidence on value.
How we work
- We tell you whether a review is worth doing before any work starts. For many homes it is not, and we will say so.
- We publish our fees, and most of our fee is paid only if a band comes down.
- We base everything on evidence about the home as it stood in 2026, because that is the value that counts.
- We keep this site up to date as the rules are settled, and date every change on the news page.
What we do not do
- We do not offer tax avoidance. We help owners pay the right amount under the rules, and no more than they legally should.
- We are independent of the Valuation Office, HMRC and local councils.
- We cannot promise a lower band. Nobody can.
- We do not give investment or financial advice about whether to keep, sell or restructure a home.
- The information on this site is general. It is not tax, legal or valuation advice for your circumstances.
Contact
The quickest way to reach us is the review form. Advisers can use the referral form. Post can be sent to SGS Ltd, PO Box 565, Guernsey GY1 6JW.
Last checked against the government's Budget documents and consultation response on 30 October 2026. The surcharge is being legislated in the Finance Bill 2026-27 and is not yet law. Some detail is still to come in regulations.