Support & Help Center

If incoming calls do not ring while the app is in the background or the screen is turned off, please verify your iOS notification and power settings:

1. Enable Notifications: Go to iOS Settings > Tsuwa > Notifications. Ensure Allow Notifications is enabled, and check Lock Screen, Notification Center, and Banners.
2. Check Focus Mode: If Do Not Disturb or Focus mode is active, incoming call alerts may be silenced. Add Tsuwa to the allowed notifications list.
3. Background App Refresh: Go to iOS Settings > General > Background App Refresh and verify that Tsuwa is turned on.
4. Network Connection: Ensure that your device has a stable internet connection (Wi-Fi or cellular). Toggling Airplane Mode on and off can help refresh network routing.

To transmit your voice, Tsuwa requires access to your device's microphone. If you declined the permission prompt during initial launch, enable it via iOS Settings:

1. Open the iOS Settings app on your device.
2. Scroll down and tap Tsuwa.
3. Toggle the Microphone switch to ON (Green). (If you plan to use video calls, enable Camera as well.)
4. Return to Tsuwa and initiate the call again.

Connection failures are typically caused by network firewalls or unstable Wi-Fi connections:

• Switch Networks: If the connection fails on Wi-Fi, try switching to cellular data (4G/5G), or vice versa.
• Restricted Networks: Corporate LANs, school campuses, and public hotspots may block WebRTC / VoIP media ports (UDP traffic).
• VPN / Proxies: If you are using a VPN, it might interfere with direct peer-to-peer routing. Try temporarily disabling your VPN to test connectivity.

Tsuwa is a next-generation hybrid calling application combining P2P WebRTC technology and SIP telephony. It offers crystal-clear, low-latency audio calls with zero user registration required, alongside seamless enterprise PBX and PSTN compatibility.

Yes, all Tsuwa app-to-app calls are 100% free of charge. Calls operate over the internet, so standard data carrier charges may apply if you are on a cellular connection (Wi-Fi recommended).

No. Tsuwa does not require phone number verification, email registration, or passwords. When you launch the app for the first time, a unique Peer ID is automatically generated for your device so you can start calling immediately.

All communications are protected by encryption (TLS/WSS). Calls (audio/video) are protected by encryption (DTLS-SRTP) upon direct device-to-device connection.

Chat messages are not end-to-end encrypted (E2EE), but are immediately erased from the server once delivery to the recipient is complete (temporary retention for up to 7 days when offline). Voice calls and messages are never persistently stored on our servers.

No. Contacts (address book), call history, and SIP/PBX configuration settings are stored exclusively on your device and are never transmitted to or collected by our servers.

To prevent impersonation and eavesdropping, a single account cannot be used simultaneously across multiple devices. Logging in on another device will automatically log you out of the previous device.

Settings and data on your device can be safely saved and migrated as an encrypted backup file protected by your own password.

Group Restriction: Completely blocks calls and messages to and from anyone outside designated groups. Calls from outside the group will not trigger notifications, so you are never disturbed by unwanted ringtones.

Ghost Call Prevention: Automatically discards and prevents outdated incoming calls that ring late due to network reception delays after the other party has already hung up.

In compliance with Apple App Store Guideline 5.1.1(v), you can delete all local data and regenerate your Peer ID at any time by going to Settings > Reset Account & Delete Data within the Tsuwa app.

Uninstalling the app also removes all local application data. To request the removal of server-side push notification tokens, you can contact our support team at support@tsuwa.kicensa.uk.