An Android app that enables payments without internet using the *99# USSD service. The app provides a modern UI for managing USSD-based payment flows via mobile network (no data connection required).

This application is NOT affiliated with, endorsed by, or approved by the National Payments Corporation of India (NPCI), the Reserve Bank of India (RBI), or any bank or telecom operator.

This is an independent, community-developed open-source project. It automates interaction with the publicly available *99# USSD service. Use at your own risk.

This application is NOT a payment system, payment aggregator, or payment gateway under the Payment and Settlement Systems Act, 2007. No license under the PSS Act is required or held.

The developers of this application assume no liability for:

• Failed, incorrect, or duplicate transactions
• Account suspension or blocking by your bank or telecom operator
• Any financial loss incurred through use of this application
• Violations of your bank's terms of service or applicable regulations

By using this application, you acknowledge that you understand the risks involved in automating USSD-based financial transactions.

See DISCLAIMER.md for the full legal disclaimer.

The app uses Android's CALL_PHONE permission to dial USSD codes (*99#) and an Accessibility Service to navigate the USSD menu dialogs automatically. All processing happens locally on your device — no data is sent to any server.

This app uses Android's Accessibility Service to read and interact with USSD dialog windows from the system phone app (com.android.phone). This is required because Android does not provide a standard API for USSD menu navigation.

Important: This usage pattern may not comply with Google Play Store policies for Accessibility Service usage. This app is intended for sideloading only and is not suitable for distribution on the Google Play Store without architectural changes.

• Send money via mobile number or payee address
• Request money
• Check account balance
• Scan QR codes for payments
• Transaction history
• Favorite recipients
• Biometric app lock
• Dark/Light/System theme support
• Dual SIM support

• Android Studio Ladybug or later
• JDK 11+
• Android SDK with API level 36

git clone <repo-url>
cd OfflineUPI
./gradlew assembleDebug

The APK will be at app/build/outputs/apk/debug/app-debug.apk.

All data is stored locally on your device only. No data is transmitted to any server. See PRIVACY_POLICY.md for details.

• Phone number (for USSD dialing)
• Contact information (names and numbers, for recipient selection)
• Transaction history (amounts, recipients, timestamps)
• Recipient list (names, identifiers)
• App preferences (theme, SIM slot, lock settings)

This application interacts with India's *99# USSD payment service, which is regulated by NPCI and RBI. Users are responsible for ensuring their use of this application complies with:

• Their bank's terms of service
• RBI regulations on digital payments
• NPCI guidelines for *99# service usage
• Payment and Settlement Systems Act, 2007
• Information Technology Act, 2000 and SPDI Rules, 2011
• Digital Personal Data Protection Act, 2023
• Prevention of Money Laundering Act, 2002
• Indian Telegraph Act, 1885 (for USSD/telecom usage)
• Consumer Protection Act, 2019
• Applicable bank-specific and telecom operator terms

This application does not hold any payment system license and is not a payment service provider, payment aggregator, or intermediary under any Indian law.

Contributions are welcome! Please read the Contributing Guidelines before getting started.

All participants are expected to follow the Code of Conduct.

Licensed under the Apache License, Version 2.0. See LICENSE for the full text.