# Privacy Policy
Effective date: April 14, 2026
Expense Tracker ("we", "our", or "us") respects your privacy. This Privacy Policy explains how the Expense Tracker app collects, uses, stores, and protects your information when you use the application.
## 1. Information We Collect
When you use Expense Tracker, we may collect the following information:
Account information: email address, password, and Firebase account identifiers used to create and access your account.
Profile information: display name you choose to add or update in your profile.
Financial tracking information: expense amounts, categories, category icons, notes, and timestamps for the expenses you create.
Budget information: your monthly budget amount and related update timestamps.
Custom category information: category names, icons, and whether a category is active or inactive.
Technical/session information: authentication session data stored locally on your device to keep you signed in.
## 2. How We Use Your Information
We use your information to:
create and manage your account;
authenticate you and keep you signed in;
store and display your expenses, budget, analytics, and categories;
personalize your in-app profile;
support core app functionality, maintenance, and security.
We do not use your expense data to sell personal information or to serve targeted advertising through the app.
## 3. Where Your Information Is Stored
Expense Tracker uses Google Firebase services, including Firebase Authentication and Cloud Firestore, to process and store data. Your information may therefore be stored on Google-managed infrastructure, subject to Google's security and privacy practices.
On mobile devices, the app also uses local device storage through AsyncStorage to preserve your authentication session.
## 4. Sharing of Information
We do not sell your personal information.
We may share information only in the following limited situations:
with service providers that operate the app infrastructure, such as Google Firebase;
when required by law, regulation, legal process, or governmental request;
to protect the rights, security, and integrity of the app or its users.
## 5. Data Retention
We keep your account and app data for as long as your account remains active or as needed to provide the service.
If you delete specific content, such as expenses or categories, that content is removed from the app database when the deletion succeeds. If you stop using the app, your information may remain stored until the account and related data are deleted from the backend.
## 6. Your Choices and Rights
Within the app, you can:
update your display name;
change your password;
create, edit, and delete expense-related content;
update your monthly budget;
add, disable, or delete categories;
log out at any time.
If you want account deletion or permanent removal of associated data, you should provide a support contact or account-deletion workflow for users.
## 7. Security
We take reasonable steps to protect your information using the security features provided by our app architecture and service providers. However, no method of electronic storage or transmission is completely secure, and we cannot guarantee absolute security.
## 8. Children's Privacy
Expense Tracker is not intended for children under 13, and we do not knowingly collect personal information from children under 13.
## 9. International Data Transfers
Because Firebase and related infrastructure may operate in different regions, your information may be processed or stored outside your country of residence.
## 10. Changes to This Privacy Policy
We may update this Privacy Policy from time to time. When we do, we will revise the effective date above. Continued use of the app after changes become effective means you accept the updated policy.
## 11. Contact Us
If you have questions about this Privacy Policy, contact us at:
Email: 6731503068@lamduan.mfu.ac.th
Project/App Name: Expense Tracker