Privacy Policy

This Privacy Policy applies to the BillSplitter group expense-splitting app — listed on Google Play as "Chia tiền khi đi du lịch nhóm" (package com.toanesc.billsplitter) and on the App Store as "BillSplitter" (also shown as "BillSplitter: Share Costs" and "BillSplitter: Chia tiền nhóm") — and to the web service at billsplitter.toanesc.com(together, "the App").

The App is developed and operated by VELUMO s.r.o.("we", "us"), the data controller for the personal data described below:

• VELUMO s.r.o., Company ID (IČO) 23424559
• Registered office: Donovalská 1661/36, Chodov, 149 00 Praha 4, Czech Republic
• Registered with the Municipal Court in Prague, section C, file 426807
• Contact: [email protected]

• Account information: display name, email address, password (stored only as a bcrypt hash) and an optional profile photo.
• Group and expense data: group names and images, bills (title, amount, currency, category, date, who paid and how it is split), receipt photos you attach, notes, comments, group fund entries, settlements, and the names of guest members you add.
• Payout accounts (optional): the bank accounts you choose to add so others can pay you back — account holder name, bank, account number or IBAN, or Revolut username, and the currency they are used for.
• Friends (optional): the people you are friends with, friend requests you sent and received, the people you blocked, and your random 8-character friend code. Other people see only your name and profile photo, never your email.
• Push notification token: a device token issued by Apple or Google (through Expo) if you allow notifications.
• Technical data: IP address and request details processed by our servers and our network provider for security, rate limiting and abuse prevention.
• Stored only on your device: your language preference and sign-in tokens.

We do not collect your location, phone contacts or advertising ID, we do not show ads, and the App contains no third-party analytics or tracking SDKs.

• To provide the service: record bills, calculate who owes whom and settle debts within your groups.
• To show members of a group the bills, balances and activity of that group.
• To show your payout account and a payment QR code (VietQR, QR Platba or a Revolut link) to group members who owe you money. The QR code is generated on our server; the App does not process payments and we never see your bank transactions.
• To let you add friends (by email, friend code or suggestions of people you shared a group with), accept or block them, and add friends to groups.
• To send notifications and emails about your groups, friend requests, debt reminders and password resets.
• To produce the optional spending analysis, which runs on a language model hosted on our own servers; your data is not sent to external AI providers.
• To authenticate you and keep the service secure.

Legal basis (GDPR): performance of the contract with you (Art. 6(1)(b)) and our legitimate interest in keeping the service secure (Art. 6(1)(f)).

We do not sell or rent personal data and do not share it for advertising. Data is visible only to members of the groups you belong to; your name and profile photo are also visible to your friends and to people you send or receive friend requests from. We use these service providers, only to run the App:

• Cloudflare, Inc. — network and HTTPS proxy in front of our servers.
• Expo (650 Industries, Inc.), Google Firebase Cloud Messaging and Apple Push Notification service — delivery of push notifications (device token and notification text).
• Exchange-rate services frankfurter.app and open.er-api.com — receive only currency codes, never personal data.

Our database and file storage run on servers operated by us in the Czech Republic (EU). We may also disclose data when required by law.

• All traffic uses HTTPS encryption.
• Passwords are hashed with bcrypt; email server credentials are encrypted at rest.
• Uploaded photos are served only to signed-in users.
• Sign-in attempts and other sensitive endpoints are rate limited.

We keep your data while your account is active. You can delete your account at any time in the App: Profile → Delete account (on the web: Settings → Delete account). Deletion takes effect immediately:

• Your name, email, phone, profile photo and password are erased and you are removed from all groups.
• Your payout accounts, friends list, friend requests, block list, friend code and push notification tokens are deleted.
• Bills you recorded in shared groups remain so the other members' balances stay correct; they show "Deleted user" instead of your name.

If you cannot sign in, email us from your account address and we will delete it for you.

Under the GDPR you may request access to, correction, deletion, restriction or portability of your data, and object to processing (bills can also be exported as CSV in the App). You may also lodge a complaint with the Czech Office for Personal Data Protection (ÚOOÚ, www.uoou.cz).

The App is not directed at children under 13 and we do not knowingly collect their data. If you believe a child has given us personal data, contact us and we will delete it.

We will post any changes on this page and update the date above.

VELUMO s.r.o., Donovalská 1661/36, 149 00 Praha 4, Czech Republic — [email protected]