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Privacy policy

Effective from 8 October 2026, version 3

This is a translation. If it differs from the Czech version, the Czech version applies.

Dlužníček is built to know only what it needs to track shared costs. It has no ads, no analytics and no third-party trackers, and we sell your data to no one.

1. Controller

The controller is Česká IT Akademie, z.s., Preslova 72/25, Smíchov, 150 00 Prague 5, Czech Republic, company ID 17863201, registered in the register of associations kept by the Municipal Court in Prague, file L 77092.

For anything about personal data, write to support@czechitacademy.cz. We have not appointed a data protection officer because the law doesn’t require us to.

2. What we process

Your account

  • the name others see in your groups,
  • your email, how you sign in (Apple, Google or email and password) and your account identifier in Firebase Authentication. If you sign in with Apple and choose to hide your email, we only get an anonymous Apple relay address. We never see the password of an email account; Firebase manages it,
  • a profile photo, if you upload one,
  • your bank account number (IBAN) and Revolut username, if you enter them. Members of your groups see them on the Pay screen,
  • the app language, when you created the account and when you last signed in.

Group content

  • group names and member names, including people without an account whom someone else added,
  • expenses, transfers and income: amounts, currencies, rates, categories, dates, notes, who paid and for whom,
  • receipt photos and the items receipt scanning reads from them,
  • your consent to AI receipt scanning and when you gave it,
  • the change history: who added, edited or deleted what and when, including earlier versions.

Loyalty cards: name, card code, note and a photo of the front if you add one, plus who a card was shared with.

Subscription: the Apple transaction identifier, subscription type, status and end date. We never see payment details; Apple handles those.

Invite a friend: your personal invite code, who invited you and who signed up through your invite, whether they started using the app, and the App Store offer code you got as a reward. The person who invited you sees how many friends signed up through them, and once you start using the app, a notification tells them your name. You see the name of the person who invited you.

Notifications: the Apple push token of your device, if you allow notifications. When you turn notifications off in your profile or sign out (including signing out of all devices at once), we delete the token. Payment notifications show the group name, the payment’s description and amount, and the name of who entered it. They are visible on the lock screen, and their text goes to the Apple Push Notification service, which delivers them.

Technical data: the server logs the type of request, the in-app address (without the tokens from invite and share links and without the parameters of website addresses) and the result. For an error it logs only what kind of error it was, never the content involved. Your IP address is kept only in memory to protect against overload, and it is not stored.

Talking to us: emails you send to support, including reports of a problem or inappropriate content in a group, and our replies.

On your phone the sign-in tokens stay in the secure iOS keychain, along with a queue of changes not yet sent. Face ID is checked by iOS itself; we have no access to biometric data.

Where the data comes from: mostly from you. Names and expenses of people without an account are entered by other group members. If someone added you to a group and you join later, you will see in that group everything they entered about you.

3. Why, and on what basis

Purpose Legal basis
Running your account, groups, calculations and settle-ups performance of a contract, i.e. these terms (Art. 6(1)(b) GDPR)
The Premium subscription and verifying it with Apple performance of a contract
Names and expenses of people without an account, entered by a group member the group members’ legitimate interest in keeping shared accounts (Art. 6(1)(f) GDPR)
Change history, backups, security and abuse prevention our legitimate interest in a reliable and secure service
The invite-a-friend reward performance of a contract
AI receipt scanning (Premium) your consent (Art. 6(1)(a) GDPR), which you give and withdraw in the app
Push notifications your consent, which you give and withdraw in iOS or in the app profile
Handling questions, requests and reported content our legitimate interest in working support; for reports also a legal obligation
Duties under the law, for example requests from authorities legal obligation (Art. 6(1)(c) GDPR)

We don’t use data for advertising, profiling or automated decision-making.

You can’t create an account without a name and a sign-in, because the app can’t work without them. Everything else, such as a profile photo, bank account number or loyalty cards, is optional.

4. Who can see the data

  • Members of your groups see the group content, your name, profile photo and the payment details you entered.
  • Processors who help us run the service:
    • the provider of the server in the Czech Republic that runs the app and its database (the server is managed by Czech IT Academy),
    • a backup storage provider in the European Union, if we keep backups outside our server. It only receives backups that are encrypted on our server first and cannot read them,
    • the provider of the mailbox we use for support,
    • Google (Firebase Authentication) for sign-in: it stores your email, name, sign-in method, account identifier and, for email accounts, the password in hashed form. Apart from receipt photos for scanning (see the next point), we never send it your expenses, groups or any other app content. This involves a transfer to the USA based on the European Commission’s adequacy decision (EU-US Data Privacy Framework) and standard contractual clauses.
    • Google (Gemini API) for receipt scanning in Premium, only if you agree to it in the app: it gets only the receipt photo, without your name or other details, and returns the items it reads. We use the paid service, under which Google does not use the photos to train its models. Google may keep the photo and its response for a limited time solely to detect abuse of the service. The transfer to the USA is on the same terms as for Firebase. You can turn your consent off at any time in your Profile. Without consent, or offline, your phone reads the receipt itself and sends it nowhere.
  • Apple acts as a separate controller when you sign in with Apple, when we send push notifications (APNs) and when you buy a subscription in the App Store. This involves a transfer to the USA based on the European Commission’s adequacy decision (EU-US Data Privacy Framework).
  • Google as a separate controller, if you sign in with a Google account, on the same terms.
  • Authorities, where the law requires it.

We download exchange rates from the Czech National Bank and send it no personal data.

5. How long we keep data

  • Account data for as long as your account exists.
  • When you delete your account we delete your profile, email, account identifier (including the Firebase account), payment details, profile photo, sign-in and push tokens, loyalty cards and subscription record.
  • If your place in a group stays after you leave or delete your account, we keep only an anonymous identifier of your former account with it. That way nobody else who gets an invite can take it over, and if you come back to the group you get it back.
  • Receipt photos are deleted 2 months after upload, together with the items read by scanning. The expense itself stays.
  • When you leave a group or the admin removes your access, your name and expenses stay in the group but are no longer linked to your account.
  • Group content belongs to all its members. Your name and expenses therefore stay in your groups so balances and history still add up for everyone else. The name is no longer linked to any account. If you’d like your name in a group changed, for example to initials, write to us or change it before deleting your account.
  • Backups are kept for up to 12 months (7 daily, 4 weekly and 12 monthly). Deleted data disappears from them as old backups expire.
  • Support emails and reports are kept while we deal with them and then for up to 3 years, so we can show how the matter was resolved.
  • Server logs have a fixed maximum size (at most 30 MB for each part of the app) and are continuously overwritten by new entries. How long an entry lasts depends on traffic, usually days to weeks.

6. Your rights

You have the right to:

  • access your data and get a copy. You can download a group’s data as CSV at any time,
  • correct inaccurate data. Most of it you can edit in the app yourself,
  • erasure, see Profile → Delete account,
  • restrict processing and to data portability,
  • object to processing based on legitimate interest,
  • withdraw consent at any time, for example by turning off notifications or AI receipt scanning in your Profile. This doesn’t affect processing that took place before you withdrew it,
  • complain to the Czech Office for Personal Data Protection (Úřad pro ochranu osobních údajů), Pplk. Sochora 27, 170 00 Prague 7, www.uoou.gov.cz.

Right to object. You can object at any time to processing we base on legitimate interest (change history, backups, security, data about people without an account). We will then stop, unless we can show compelling legitimate grounds that override your interests, or we need the data to establish or defend legal claims.

To use your rights, email support@czechitacademy.cz, ideally from the address linked to your account. If we can’t be sure the request comes from you, we may ask you to verify it. It’s free of charge. We reply within one month. If someone who was added to a group without an account contacts us, we will change or remove their name in that group.

7. Security

All communication with the app is encrypted (HTTPS). Sign-in tokens are stored on the server only as hashes, group access is checked on every request, and backups are encrypted. In your Profile you can sign out of all devices at once, for example when you lose your phone. If a breach ever put you at risk, we would tell you.

8. Children

Dlužníček is for people aged 15 and over. If we find out that someone younger has created an account, we will delete it.

9. This website

The website dluznicek.czechitacademy.cz uses no cookies, no analytics and no third-party content. Fonts and images load from our own server. The one exception is the page for confirming your email and resetting your password (/en/verify): it sends the code from the email, and a new password if you set one, straight to Google’s Firebase Authentication. The server may briefly log technical details of requests for operation and security.

10. Changes

We may update this policy when the app or the law changes. We will announce material changes in the app or on this website in advance.

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