Privacy Policy

Controller

George Patsalos, Martinistraße 8, 28195 Bremen, Deutschland. georgepatsalos@gmail.com.

Principle: your data stays with you

The calculator runs entirely on your device. Everything you enter — profile, income, deductions, taxpayers, years — is stored only in your browser's or device's local storage. We operate no server that receives your entries: your tax data is never transmitted to us, and we can neither view nor analyse it.

Using the calculator requires signing in — with a Google account or with an email account. With Google your data is written to your own Google Drive so that it belongs to you rather than to this browser and you can continue on another device; it goes to you and to your storage provider, not to us. With an email account your entries stay on this device. See the sections “Signing in with Google” and “Email account”.

We use no analytics, tracking or advertising services and no cookies for such purposes.

You can export your data as a JSON file at any time, import it again or delete it within the app. Clearing site data in your browser removes all stored entries permanently.

Hosting

The application is delivered as static files by Vercel Inc., 440 N Barranca Ave #4133, Covina, CA 91723, USA. When you open it, the hosting provider processes technically necessary connection data (IP address, time, requested file, browser identifier) to serve the page and keep the service secure (Art. 6(1)(f) GDPR). This data contains none of your tax entries. Details: vercel.com/legal/privacy-policy.

Distance lookup (only when you trigger it)

If you ask the app to calculate the distance between home and workplace, the addresses you entered are sent to the selected map service — OpenStreetMap (Nominatim and OSRM) or, with your own key, Google Maps. This happens only when you explicitly trigger the lookup. Without this feature no address data leaves your device.

Signing in with Google and syncing to your Drive (one of the two ways to sign in)

Signing in is required to use the calculator — with a Google account or with an email account; this section concerns signing in with Google. The legal basis is performance of the user relationship (Art. 6(1)(b) GDPR), to the extent the sign-in is necessary for it. You may stop using the service at any time by signing out or revoking the permission in your Google account; the file in your Drive belongs to you and stays with you.

For storage, only the “drive.file” scope is requested. It grants access to files and folders this calculator creates in your Drive, plus documents you explicitly select in the Google Drive file chooser. Importing saves an evidence copy and leaves the original unchanged. There is no general access to your other files, mail, calendar or contacts. In addition “openid”, “email” and “profile” are requested so the app can show which of your accounts is being written to.

Once connected, your tax data, uploaded supporting documents and generated reports are backed up automatically to your own Google Drive. The recipient is Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland, as the provider of your storage service; their privacy policy applies (policies.google.com/privacy). Changes sync in the background. Offline changes remain on this device and are transferred after reconnection. Signing out stops synchronization.

Your name, email address and the link to your profile picture are held only in the local storage of your device, in order to show them in the profile area. They are not transmitted to us. Signing out deletes them from your device; your tax data is kept. The short-lived access token is held in memory only and is never stored.

The file created in your Drive belongs to you. You can view, download or delete it there at any time; we have no access to it.

Email account and two-factor sign-in (one of the two ways to sign in)

Instead of Google you can sign in with an email account or create one. The account service is operated on our behalf by Supabase, Inc., 970 Toa Payoh North #07-04, Singapore; the project is hosted in the Frankfurt (EU) region and a data-processing agreement under Art. 28 GDPR applies (supabase.com/privacy). The legal basis is performance of the user relationship (Art. 6(1)(b) GDPR).

The account service holds only the account data: your email address, the password in hashed form (never in plain text), the secret required for two-factor sign-in where you enable it, and technical sign-in data (timestamps, sign-in IP address). Your tax entries never reach the account service — with this way of signing in they stay on your device.

When you create the account you receive a confirmation email; only its link makes the account usable. Two-factor sign-in with an authenticator app is turned on and off in the Security section of the profile; the secret is created during setup and is never seen by us.

Signing out deletes the session from your device and revokes it with the service. You can request deletion of the account itself at any time via the address in the legal notice (Art. 17 GDPR); your locally stored entries are unaffected.

Your rights

Since we never receive your entries, we cannot view, hand over or delete them — you do that yourself on your device. Where the hosting provider processes connection data, you have the rights under Art. 15 to 21 GDPR (access, rectification, erasure, restriction, portability, objection) and the right to lodge a complaint with a supervisory authority.

Changes

If features are added that transmit data, this notice will be updated first. Last updated: September 2026.