Challenge Mansion Tax
Last updated 8 November 2026

Privacy policy

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. We are the data controller for the personal information described here and are registered with the Information Commissioner's Office (ICO registration number ZC294965).

Contact: info@challengemansiontax.co.uk

What we collect

  • When you ask for your report or the free guide: your name, email address, property postcode, and the checker result at that moment (estimated value or range, band, yearly charge and projected total), plus the details you gave the checker (property type, floor area, and optionally condition, lease length, floor level and address) so we can produce your report.
  • If you choose to add it after signing up: your property address, so we can alert you when your home's valuation is published.
  • If you tick the optional WhatsApp box: your mobile number and the date you agreed, so we can send you mansion tax updates on WhatsApp.
  • When you request a personalised preview: your name, email address, your home's address, postcode and details (property type and floor area, or the details you gave the checker), whether you confirmed you are a homeowner, and when you asked for and opened the sample. We use these to work out the personalised pages of your sample.
  • When you ask for a free consultation: your name, email address, phone number, postcode, the best time to call and anything you tell us.
  • When you order a Property Value Evidence Pack: your name, email address, phone number, your home's address and details, anything else you tell us about it, any photos or documents you send, your request for us to start work, and a record of your payment.
  • When you email us: your message and contact details.

When you use "Estimate my value", your postcode and the property details you enter are sent to our server to work out the estimate. We do not store them with anything that identifies you: we keep only the postcode district (for example SW3), the property type and the result, to produce our own market statistics. "I know my value" runs in your browser, and figures you type there are not sent to us unless you submit the form.

Why we use it, and our lawful basis

  • To send you the report and guide you asked for. Our lawful basis is our legitimate interest in providing the service you requested.
  • If you tick the optional box: to email you updates about the mansion tax, for example when the rules or valuations change. Our lawful basis is your consent, which you can withdraw at any time.
  • If you tick the WhatsApp box: to send you mansion tax updates on WhatsApp. Our lawful basis is your consent, which you can withdraw at any time by replying STOP or emailing us.
  • If you give us your address: to tell you when your home appears on the draft valuation list and the value it has been given. Our lawful basis is your consent, which you can withdraw at any time.
  • To tailor those emails to your band and area, for example sharing local sales evidence for your postcode. This is covered by the same consent.
  • To arrange and hold a free consultation you asked for. Our lawful basis is our legitimate interest in providing the service you requested.
  • To prepare a personalised preview for your home, to send it, and to mark your copy with your name and email so it stays personal to you. Two days later we send one follow-up email about ordering a Property Value Evidence Pack, unless you have already ordered. Our lawful basis is our legitimate interest in providing the sample you asked for, following it up and protecting our work. You can unsubscribe from the follow-up at any time.
  • To carry out a Property Value Evidence Pack or the Appeals Service you have ordered, take payment and keep records of it. Our lawful basis is to perform our contract with you, and to meet our legal obligations, such as keeping tax records.
  • To answer your questions. Our lawful basis is our legitimate interest in responding to you.

We do not sell your information. We will not pass your details to any partner, such as a surveyor or estate agent, unless you ask us to.

Who processes it for us

  • Netlify hosts this website and stores form submissions.
  • MailerLite stores our email lists and sends our emails, including the email with your report and guide.
  • Namecheap provides our email inbox.
  • Our payment provider, PayPal, takes payments for our paid services. We don't see or store your card details.
  • Meta (Facebook) and Google, only if you accept advertising cookies: which pages you visit and whether you signed up or started an order, to measure our ads (see Cookies below).
  • WhatsApp (Meta) delivers our WhatsApp updates, if you ask for them.

Some of these providers may process data outside the UK. Where they do, they use safeguards approved under UK data protection law, such as the International Data Transfer Addendum.

How long we keep it

We keep your details until you unsubscribe, or for up to 12 months after the mansion tax challenge window for the current valuation list closes, whichever is sooner. After that we delete them. If you order a paid service, we keep the order and payment records for six years, as UK tax rules require.

Your rights

You can ask to see, correct or delete the information we hold about you, object to how we use it, or withdraw consent. Every email has an unsubscribe link, or you can email us. If you are unhappy with how we handle your information, you can complain to the Information Commissioner's Office at ico.org.uk.

Cookies

We use Cloudflare Web Analytics to count visits and see which pages are read. It does not set cookies, does not track you across other websites and does not identify you, so it runs for every visitor.

Meta (Facebook) pixel and Google tag, only if you accept. When you first visit, a banner asks whether we may use advertising cookies. If you tap Accept, the Meta pixel and the Google tag (for Google Ads) set cookies (such as Meta's _fbp and Google's _gcl_au and _ga, kept for up to about 13 months) so Meta and Google can tell us which of our ads bring visitors, sign-ups and orders, and show our ads to people likely to be interested. We send them only the page visited and the type of action (for example "sign-up" or "order started", with the price for orders). We never send your name, email, postcode, address or your home's details. Meta Platforms Ireland Ltd and Google Ireland Ltd are responsible for how they use this information; see Meta's privacy policy and Google's privacy policy. Our lawful basis is your consent.

If you tap Reject, or don't choose, neither is loaded and no advertising cookies are set. Your choice is remembered on this device. You can change it at any time: cookie settings (also at the bottom of every page).