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FAQ and Troubleshooting

github-actions[bot] edited this page Aug 11, 2026 · 3 revisions

❓ FAQ & Troubleshooting Guide

Welcome to the Secure Dialer FAQ & Troubleshooting Guide. Search below for solutions to common configuration questions, default app setups, dual-SIM preferences, and custom ROM integration.


📱 Section 1: Default Phone App & System Integration

Q1: Why does Secure Dialer ask to be set as the Default Phone App?

A: Android OS architecture strictly requires dialer applications to be registered as the system Default Dialing App in order to handle active incoming/outgoing call screens (InCallService), access cellular hardware controls (TelecomManager), and update call logs (CallLog).

Q2: How do I set Secure Dialer as my default dialer on Samsung / Pixel / Xiaomi / OnePlus?

  1. Open your device's System Settings.
  2. Navigate to Apps -> Default Apps.
  3. Tap Phone App (or Default Dialer) and select Secure Dialer.
  4. (Optional for Xiaomi / HyperOS / MIUI): Open Autostart permissions and grant Autostart to Secure Dialer to ensure incoming calls wake the screen instantly when locked.

🚫 Section 2: Call Screening, Spam Blocking & Blacklists

Q3: How do I activate offline Call Screening & Spam Rejection?

  1. Open System Settings -> Apps -> Default Apps.
  2. Tap Caller ID & Spam App (or Call Screening Service).
  3. Select Secure Dialer.
  4. Inside Secure Dialer -> Settings -> Call Screening & Blocklist:
    • Toggle Enable Offline Call Screening.
    • Choose blocking rules: Block Blocklisted Numbers, Block Private/Hidden Numbers, or Block Unknown Numbers.

Note

100% Offline Screening: Unlike cloud-based caller ID services (e.g. Truecaller), Secure Dialer screens calls locally using your encrypted on-device database in under 5 milliseconds with zero internet access.


📶 Section 3: Dual-SIM Calling & Carrier Preferences

Q4: Does Secure Dialer support Dual-SIM smartphones?

A: Yes! Secure Dialer natively detects multi-SIM hardware slots (SubscriptionManager). When placing a call:

  • A fluid SIM selector prompt appears allowing you to tap SIM 1 or SIM 2.
  • You can configure a default SIM preference per contact or globally in Settings -> Dual-SIM Preferences.

🔒 Section 4: Custom ROMs (GrapheneOS / CalyxOS / LineageOS / /e/OS)

Q5: Is Secure Dialer compatible with GrapheneOS and de-Googled Android ROMs?

A: 100% Compatible. Secure Dialer is engineered specifically for privacy-hardened and de-Googled operating systems. It does not contain or depend on Google Play Services, Firebase Cloud Messaging, or microG components.


💾 Section 5: Local Backup, Migration & Data Security

Q6: How do I backup my call history, speed dial settings, and local encrypted contacts?

  1. Open Secure Dialer -> Settings -> Data & Backup.
  2. Tap Export Encrypted Backup (.vcf / .json).
  3. Choose a destination folder on your internal storage or external SD card.
  4. To restore on a new smartphone, tap Import Backup and select your saved backup file.

[!SECURITY] Data Ownership: Your backups remain strictly on your physical storage device. Make sure to keep your exported backup files in a safe location or encrypted container.


📍 Quick Links: Home | Wall of Honor | Installation and Obtainium Guide | Permissions and Privacy Explained | Security and Encryption Architecture

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