Your Data Is Never Stored
Your broker CSV contains your entire trading history – every buy, sell, dividend, and corporate action. That's sensitive data. Before uploading it to any online tool, you should know exactly what happens to it. Here's how our calculator works.
Nothing is stored
When you use our CGT Calculator, your broker file is processed and the result is shown on screen. That's it. We don't save your file, your transactions, or your report to any database. When you close the tab, the data is gone.
There is no account, no login, and no "calculation history" feature – because we never store anything to show you later.
How the calculation actually works
When you upload your broker CSV, it is sent over an encrypted connection to our server, where it is processed entirely in memory. The engine applies HMRC's matching rules, converts foreign currencies, and processes options strategies, then returns your report. Your file is never written to disk and never saved to a database.
Your broker file is sent over an encrypted connection and processed in memory to build your report, then discarded. We write nothing to disk — our database has zero records of your trades.
Your upload travels over an encrypted (HTTPS) connection and is held only in memory for the moment it takes to build your report. Once the report is generated, the data is discarded – there is no copy left on our servers.
No tracking, no ads
We use Vercel Web Analytics for basic page view counts. It doesn't collect personal data, doesn't use cookies, and doesn't fingerprint your browser. It's privacy-compliant by design.
We don't use Google Analytics, Facebook Pixel, or any advertising tracker. We don't sell data to anyone. There are no third-party scripts tracking your behaviour on the site.
Nothing to breach
Because we don't store your financial data, there is nothing for an attacker to steal. If our server were compromised, they would find zero transaction records – because we don't keep any.
This is a deliberate design choice. Many online tax tools store your data so they can offer features like "compare with last year" or "auto-fill from previous submission". We chose not to – your data is never ours to keep.
For more detail, see our Privacy & Security documentation.