Privacy
Last updated 13 August 2026
Your salary, your savings, your mortgage balance and everything else you type into this site stay in your browser. They are not sent anywhere, not stored anywhere, and not seen by anyone — including us. That is not a policy anyone has to keep to. It is how the site is built, and the rest of this page is the detail.
The short version
- No account, no sign-in, no database.
- Every figure you enter is worked out in your own browser and never leaves it.
- No analytics, no advertising, no tracking, no third-party scripts.
- No cookies. Two small settings are kept on your device only, and neither identifies you.
- The company hosting the site records ordinary web request logs. Nothing financial is in them.
Why your figures stay put
There is no server to send them to. Every page here is a file, and the arithmetic runs as code inside your browser. When you fill in the calculator, nothing is submitted: the answer appears because your own device worked it out.
That is backed up rather than left to trust. The site tells your browser, in a policy it ships with every page, that it is not permitted to make network requests at all. If a script were ever added that tried to send your figures somewhere, your browser would refuse it. The typefaces are served from this site rather than from a font service, for the same reason — a tool whose claim is that your salary stays in your browser cannot be quietly asking someone else's server for anything.
The forms on the site do not submit either. Both of them — the correction form and the sign-up for the worked examples — open your own email app with a message ready to send. Nothing goes anywhere until you press send there, and nothing passes through us on the way.
What is kept on your device
Two settings, both stored by your browser rather than sent to us, both containing a single word, and neither identifying anybody:
- Your theme. If you switch the site to dark, that choice is remembered so the page does not flash white the next time you visit.
- Whether you have already been asked to sign up. The worked examples ask for an email address the first time you open one. Once you have answered — either way, including by skipping it — that is remembered so you are not asked again.
Neither is a cookie and neither is ever transmitted. Clearing your browser's site data for this site removes both. There is no other storage, and nothing here needs a consent banner, which is why there isn't one.
If you do type an address into that sign-up, it goes nowhere near a server: it composes a message in your own email app, exactly like the correction form, and it is not sent until you press send there.
What is in a result link
When you reach a result, the address bar carries the whole scenario so you can bookmark it or come back to it later. Two things are worth knowing about that.
It sits in the part of the address after the # symbol — and your browser never sends that part to any server, not when it requests the page and not when you click a link away from it. So even though the address contains your figures, they do not reach our host's logs, anyone else's logs, or the site you click through to. This is the reason it is stored there rather than in the ordinary part of a web address, which would reach all of those.
But the link itself contains your figures. If you send it to someone, paste it into a chat, or leave it in a shared browser's history, whoever has the link can open your result. Share it deliberately, the way you would share anything else about your money.
What the host sees
The site's files are served by Cloudflare, Inc., and like any web host it keeps request logs. Those record the address of the page requested, the time, your IP address, and what browser made the request. That happens for every website you visit and is what allows a site to be served and protected from attack.
What is not in those logs is anything financial. The scenario lives in the part of the address that is never transmitted, so there is no request in which it could appear. The tool page itself is also kept out of search engines, so a result address is not something a crawler can find and index.
Those logs are the host's, held under its own terms and retention, and we do not build anything on top of them: there is no analytics account, no dashboard, no profile of a visitor. Where UK data protection law treats an IP address in a server log as personal data, the basis for it is legitimate interests — serving the site and keeping it up.
If you write to us
Emailing [email protected] means we hold your message and your address, in an ordinary mailbox, for as long as it takes to deal with what you wrote and a reasonable period afterwards. It is not added to a list, not used for marketing, and not passed to anyone.
Please do not send figures you would rather keep private. There is never any need to: if something looks wrong on a result, send the result link, and it opens the same screen you were looking at.
Your rights
UK data protection law gives you rights over personal data held about you — access, correction, erasure, objection, and the right to complain. For this site the practical answer is unusual: apart from an email you have chosen to send, and the host's request logs, there is nothing held to exercise them over. If you want to ask anyway, write to [email protected].
If you are not satisfied with the answer, you can complain to the Information Commissioner's Office, the UK's data protection regulator, at ico.org.uk.
Children
This is a tool for people buying property. It is not aimed at children and asks nobody their age, because it asks nobody anything that is stored.
If that ever changes
A paid version is planned, where you could save a scenario and be told when rates or tax thresholds move. It does not exist yet, and nothing on this site today asks you to create an account or takes a payment.
When it arrives it will hold an email address and the date your access runs to — and nothing else about you. Saved scenarios will be encrypted in your browser under a passphrase that never leaves it, so what is stored is a block of bytes that cannot be read by us or by anyone who obtains it, including the name you gave it. That version will have its own notice, published before anyone can sign up.
Who we are
After the deposit is run from the United Kingdom, under the law of England and Wales. The contact address is [email protected].
If this notice changes in substance, the date at the top changes with it.