Last updated: September 12, 2026
1.1. This Privacy Policy governs the collection, handling, and storage of information when using the Quartal mobile application (hereinafter referred to as the "App") and the website quartal.app.
1.2. Quartal is engineered around the "Zero-Knowledge & Local-First" principle — we deeply respect user privacy and eliminate personal financial data storage on our servers entirely.
2.1. All your financial transactions, income, expenses, tax calculations, FOP profile settings, KVED industry codes, client directories, and saved counterparties are stored EXCLUSIVELY LOCALLY in the sandboxed secure storage of your mobile device (AsyncStorage / SQLite / Secure Store).
2.2. The Developer DOES NOT collect, transmit to proprietary servers, store, or have technical access to your accounting ledger, financial records, transaction history, or generated primary documents.
2.3. If you delete the App from your device or reset device memory, all local data is permanently wiped unless you manually exported a backup file or report beforehand.
3.1. Bank API Tokens (Monobank, PrivatBank, A-Bank, etc.): Stored exclusively in the hardware-backed encrypted keystore of your smartphone (iOS Keychain / Android Keystore) and used only for direct HTTPS requests between your device and official banking servers in read-only mode. Tokens are never transmitted to Quartal servers.
3.2. Electronic Digital Signature Keys (QES / CEP): When generating or signing documents, file keys and passwords are processed locally on your device by cryptographic libraries. The Developer never stores your passwords and has zero access to your digital signature.
3.3. Third-Party Integrations (Dubidoc, Checkbox, WayForPay, etc.): Interactions with these external services occur directly using the User's personal API keys. The Developer assumes no responsibility for data processing or storage conducted by these independent third-party services under their respective privacy policies.
4.1. If you utilize operating system backup services (Apple iCloud Backup, Google One, Android Backup), an encrypted copy of App data may be included in your personal OS cloud backup.
4.2. The Developer does not control or manage these cloud backups and assumes no liability for the integrity, security, or unauthorized access to your personal Apple ID or Google Account.
5.1. To monitor application stability, troubleshoot crashes, and optimize the user experience, the App may utilize industry-standard platform SDKs:
5.2. No analytics service ever receives your bank statements, income amounts, or personal tax identification numbers (RNOKPP/EDRPOU).
6.1. Because all sensitive financial data is stored directly on your hardware, the User is solely responsible for restricting physical and digital access to their device.
6.2. We strongly recommend enabling biometric authentication (Face ID / Touch ID / Fingerprint), maintaining a strong device passcode, and never running the App on compromised devices (Jailbroken / Rooted), which disable operating system sandboxing security.
7.1. We reserve the right to revise this Privacy Policy periodically. The effective version is always accessible at quartal.app/privacy-policy-en.html.
7.2. For any inquiries regarding privacy and data practices, please reach out to us at support@quartal.app.