What we send,
and what we don't

This site sets no cookies, runs no analytics and includes no tracking scripts. Fonts are served from this domain, not a font CDN, so loading a page contacts no third party at all.

The three free tools do run code: the tax engine, compiled to WebAssembly, executing in your browser tab. The figures you type — and any file you drop into the compatibility checker — are processed there and are not transmitted anywhere. There is no endpoint to transmit them to, and the site's Content Security Policy restricts connections to this origin, so that is enforced by the browser rather than promised by us. You can confirm it in your browser's network tab while you use the tools.

Our host, Cloudflare, processes request logs (IP address, user agent, URL) as part of serving the site, as any web host does. We do not join that to anything else, and we do not have any other record of your visit.

Your transaction files, the figures computed from them, and any saved session stay on your computer. They are read locally, computed locally and stored locally; we operate no server that receives them, and there is no account to create.

What the application does contact, and why

• Update checks. The app asks our update service whether a newer version exists. That request carries the current version and the platform, and it is how a fix reaches you. No portfolio data is included.
• Licence validation. When licensing is live, activating a licence key will contact our payment provider's service. That carries the key, not your holdings.
• Whatever you deliberately send us. If you email a broker export so we can add support for your platform, we have that file because you sent it. We ask for redacted files, we use them only to build and test an importer, and you can ask us to delete one.

The operating system's webview — the qualification that matters

Because your financial records stay on your device, we are not a data controller for them — we never receive them. Where we do hold personal data, it is the ordinary minimum: emails you send us, and purchase records our payment provider holds as merchant of record. Longstop Software Ltd is registered in England and Wales, company number 17359840, and you can ask us what we hold, ask for it to be corrected, or ask us to erase it: hello@longstopsoftware.com.

GainPool is a calculation aid. It produces an estimated Capital Gains position from the records you give it. It is not a filing service, it submits nothing to HMRC, and it is not a substitute for advice from a qualified accountant. Its scope and limitations are stated in the application itself, on screen, before any figures are shown — and also here.

You remain responsible for what goes on your tax return. That is not a disclaimer we are hiding behind; it is why the app exports a computation pack showing how every figure was reached, so you or your accountant can check it rather than take it on trust.

GainPool is not yet available to buy. Before it is, we will publish here: the full licence terms, the refund window, a matrix of exactly which scenarios are supported, and the response time you can actually expect from support — a small company's honest number, not a marketing one.

Your statutory rights as a consumer buying digital content in the UK apply regardless of anything we publish, including the 14-day cancellation right under the Consumer Contracts Regulations 2013.

Support is email, to the address on this page, read by a person.

Material changes will be dated here. Last updated 31 July 2026.