Privacy Policy

Last updated: 21 July 2026

This policy explains what data Deudin collects, why, and what you can do about it. We collect as little as we can to run the app, and we don't sell your data or run ad tracking.

The short version

We collect your email, a display name, and the expenses and payments you record.
We use it to run the app and sync your groups across devices — nothing else.
We don't sell your data and we don't use advertising trackers.
You can export a group's full history at any time, and ask us to delete your account.

What we collect

Account details: the email address you sign up with and your display name. Your raw email is never shown to other members — they see your display name.
Sign-in credentials: if you use a passkey, we store the public key your device generates. We never see or store your device's private key, your fingerprint or your face.
Your group data: groups, members, expenses, payments, splits, notes and the activity history you create.
Notifications: if you turn on push notifications for a group, we store the subscription your browser provides so we can send those alerts.
Minimal technical data: basic, aggregated request and error information needed to keep the service running and secure.

How we use it

To provide the app: store your ledger, keep balances correct, and sync them live across everyone in a group.
To sign you in securely and keep your account safe.
To send the push notifications you've opted into (your own actions never notify you).
To fix bugs, prevent abuse, and understand roughly how the app is used so we can improve it.

Where your data is stored

Deudin runs on Cloudflare's platform. Your data is stored and synced there so the app works across your devices and the members of your groups. These providers process data on our behalf and only to run the service.

Analytics

We use privacy-friendly, cookieless analytics (Cloudflare Web Analytics) to see aggregate traffic — page views and referrers. It doesn't use tracking cookies, doesn't fingerprint you, and doesn't build a profile of you across sites.

We don't sell your personal data and we don't share it with advertisers. Data within a group is visible to the members of that group. We only share data with the infrastructure providers above, or if the law requires it.

Your choices and rights

Access and export: group owners can export a group's full history to a CSV at any time.
Correction: you can edit your display name and your entries directly in the app.
Deletion: you can ask us to delete your account and the data tied to it. Note that entries you added to a shared group are part of that group's ledger for the other members.
Notifications: turn push notifications off per group, or in your device settings, whenever you like.

Data retention

We keep your data for as long as your account is active or as needed to run the service. When you delete your account, we remove your personal data within a reasonable period, except where we must keep something to comply with the law.

Children

Deudin isn't directed at children under 13, and we don't knowingly collect their data. If you believe a child has given us personal data, contact us and we'll remove it.

Changes to this policy

We may update this policy as the app evolves. When we make a meaningful change we'll update the date above.

Contact

You can reach us through the Send feedback option in the app's avatar menu, or by reporting a bug from the same place.