TripBudget – Privacy Policy

Last Updated: December 11, 2025

TripBudget is operated by:

Louis Breyne, Operating under the trade name "Breyne Engineering"

Independent entrepreneur registered in Belgium

VAT number: BE1008.222.750

1. Introduction

This Privacy Policy describes the manner in which TripBudget (“TripBudget”, “we”, “our”, “us”) processes personal data relating to users of the TripBudget mobile application and associated web-based services (collectively, the “Service”). The Policy explains the nature of the personal data we collect or receive, the purposes for which such data are processed, the legal bases that justify the processing, the rights granted to data subjects under applicable data protection laws—including Regulation (EU) 2016/679 (the “General Data Protection Regulation” or “GDPR”)—and the measures we implement to protect personal data.

TripBudget is designed according to a privacy-first and offline-first architecture. Users may access and use the Service in a fully offline environment where no account is required and no personal data is transmitted to servers under our control. Users may alternatively activate Online Mode, which enables synchronization across devices and the sharing of trip data through Google Firebase infrastructure. Only data associated with trips expressly published by the user for cloud synchronization are transmitted beyond the device.

By using the Service, installing it, or creating an account when electing to use Online Mode, you acknowledge that you have read and understood this Privacy Policy. If you do not agree with its terms, you must not use the Service.

2. Scope of the Policy

This Privacy Policy applies to all processing of personal data executed by TripBudget, whether the processing relates to Local Mode or Online Mode. It does not apply to third-party services that are not under our control, including external websites accessed through invitation or help links, nor does it extend to data processed independently by participants with whom a user shares trip information.

3. Definitions

For purposes of this Policy, “personal data” refers to any information relating to an identified or identifiable natural person, as defined under the GDPR. “Processing” refers to any operation performed on personal data, including collection, storage, transmission, alteration, and deletion. “Controller” refers to the legal entity that determines the purposes and means of processing personal data, which is Breyne Engineering for all data processed by the Service.

4. Categories of Data Processed

4.1. Data Processed in Local Mode

Local Mode allows full use of the Service without creating an account. In this mode, all data is stored exclusively on the user's device and remains inaccessible to us or any third party unless explicitly exported or shared by the user.

Data stored locally may include: – trip information (titles, dates, currencies, budgets, stages), – participant names and optional emails entered manually by the user, – expenses, contributions, payment dates, application dates, locations (city/country as text), categories, notes, and exchange-rate information, – metadata required for internal calculations, including normalized amounts, spread configurations, timestamps, and identification numbers related to trips or expenses.

We do not collect or receive any of this data unless the user publishes a trip to the cloud. Local Mode processing remains entirely under the user’s control. Removal of the application will result in irreversible deletion of all locally stored data.

4.2. Data Processed in Online Mode

When Online Mode is enabled, users may authenticate using Google Sign-In or using Email and Password via Firebase Authentication. In this mode, data required for synchronization across devices and for collaborative use of shared trips is transmitted to and stored in Google Cloud Firestore.

In Online Mode, we process: – authentication data consisting of the user’s email address, display name (if provided by Google), anonymized Firebase User ID, and authentication tokens, – trip data explicitly published by the user, including all participants, expenses, categories, contributions, stages, and related metadata, – derived data generated by the Service such as timestamps of updates, internal identifiers, and synchronization state information.

We do not have access to user passwords. Passwords for Email/Password authentication are processed solely by Firebase using industry-standard hashing mechanisms and are never accessible to us.

5. Purposes of Processing

Personal data are processed only to the extent necessary for the operation, maintenance, and improvement of the Service. In Local Mode, all processing is performed locally on the user’s device and never transmitted externally.

In Online Mode, personal data are processed for the following purposes: – to create and manage user accounts and authenticate user access; – to enable synchronization of user-selected trips across devices; – to allow collaborative use of trips where multiple participants access or modify the same trip data; – to ensure the accuracy and security of the synchronization process, including conflict resolution and data integrity; – to provide user-requested support and handle GDPR-related requests; – to comply with any applicable legal obligations.

TripBudget does not engage in behavioral profiling, targeted advertising, commercial resale of data, or any secondary processing unrelated to the provision of the Service described herein.

6. Legal Bases for Processing

We rely upon one or more of the following legal bases for the processing of personal data under GDPR:

Performance of a contract (Art. 6(1)(b)): Processing necessary to provide the Service, including account creation, synchronization, and collaborative functionality.

Consent (Art. 6(1)(a)): Processing that requires user activation of Online Mode, submission of optional information (such as participant emails or notes), or the request of support communications. Users may withdraw consent at any time by disabling Online Mode or requesting deletion of their account.

Compliance with legal obligations (Art. 6(1)(c)): Processing required for statutory obligations, including security and record retention.

Legitimate interests (Art. 6(1)(f)): Processing necessary for ensuring the security, stability, and proper functioning of the Service, provided such interests are not overridden by the rights and freedoms of data subjects.

7. Data Retention Periods

Data stored locally on a user’s device is retained solely at the user’s discretion and is permanently deleted when the application is removed or when the user elects to delete individual trips. We do not access, store, or retain local data.

Data synchronized to Google Cloud Firestore in Online Mode is retained for as long as the user maintains the associated trip or account. When a user deletes a trip, all associated cloud data is permanently removed. Users may request complete deletion of their Firebase account and all related data by contacting support@tripbudget.app .

Firebase Authentication may retain certain logs for limited periods for security and fraud-prevention purposes, as required under its Terms of Service.

8. Data Sharing and International Transfers

TripBudget does not sell, rent, or otherwise transfer personal data to unrelated third parties. Data may be shared only in the following circumstances:

Google Firebase (Data Processor) TripBudget relies on Google Firebase services—including Authentication and Firestore—to provide Online Mode functionality. Personal data published to cloud storage is hosted on Google infrastructure, which may involve transfers outside the European Economic Area. These transfers are safeguarded by Standard Contractual Clauses (SCCs) and by Google’s binding corporate rules.

Collaborative Trip Sharing When users publish a trip to the cloud and invite participants, the data associated with that trip becomes accessible to each participant. Users are responsible for the personal data they voluntarily include in a shared trip.

Legal Compliance We may disclose personal data where required to comply with applicable law, legal proceedings, or law enforcement requests.

No personal data is transmitted to currency exchange-rate providers when fetching rate information; such requests are made without user-identifying parameters.

9. Data Security Measures

TripBudget implements a combination of technical and organizational measures designed to ensure the confidentiality, integrity, availability, and resilience of personal data processing. These include, but are not limited to:

– encryption of data in transit using TLS and encryption at rest using AES-256 for all data stored in Firebase; – strong authentication mechanisms via OAuth2 or secure password hashing; – strict Firebase Security Rules limiting access to trip data exclusively to the trip owner and authorized participants; – OS-level storage protections for local data stored within the secure private application directory; – internal procedures for access control, minimization of logged data, and prevention of unauthorized access.

While no digital system can guarantee absolute security, TripBudget undertakes reasonable efforts to protect personal information from accidental or unlawful destruction, loss, alteration, unauthorized access, or disclosure.

10. Data Subjects’ Rights

Under the GDPR, users have the following rights with respect to their personal data:

Right of Access: to obtain confirmation of whether personal data concerning them is processed and, if so, to receive a copy of such data.

Right to Rectification: to correct inaccurate or incomplete personal data.

Right to Erasure: to request deletion of personal data, including the right to have all cloud-synchronized trips and accounts removed. Local Mode data must be deleted directly on the device.

Right to Restrict Processing: to request that processing be limited in certain circumstances.

Right to Data Portability: to receive their personal data in a structured, commonly used, and machine-readable format. Users may export trip data via CSV using the in-app export function.

Right to Object: to object to processing where permitted by law.

Right Not to Be Subject to Automated Decision-Making: TripBudget does not implement automated decision-making producing legal or similarly significant effects.

Users may exercise these rights by contacting support@tripbudget.app . We may request verification of identity where necessary to protect user data.

11. Children’s Data

TripBudget is not directed toward children under the age of 16 and does not intentionally process personal data belonging to minors. If we become aware that data of a minor has been collected inadvertently, we will take appropriate steps to delete such data without undue delay.

12. External Links

The Service may contain links to external websites, such as documentation or invitation pages. TripBudget is not responsible for the privacy practices of third-party websites, and users are encouraged to review the privacy statements of such websites prior to interacting with them.

13. Amendments to This Policy

We reserve the right to update or amend this Privacy Policy from time to time in response to changes in legal obligations, technological developments, or modifications to the Service. Any changes will be published on https://tripbudget.app/privacy , and the “Last Updated” date will be revised accordingly. Continued use of the Service after such changes constitutes acceptance of the updated Policy.

14. Contact Information

For any concerns, requests, or questions relating to this Privacy Policy or to the processing of personal data, users may contact:

TripBudget Privacy Office

Email: support@tripbudget.app

Website: https://tripbudget.app

Users in the European Union also have the right to lodge a complaint with their national Data Protection Authority if they believe their rights have been infringed.