VettedCalls works on every Android phone — no special app development, no Android version lockout. The architecture is dead simple: a free SIP softphone (3CX) hosts your VettedCalls extension, your carrier forwards calls to VettedCalls, and screened calls ring back to your extension over data.
Why this architecture works
Android exposes a system-level API called CallScreeningService. In theory, a dedicated app could intercept inbound calls before the ringer fires. In practice, every Android version, every OEM skin (Samsung, Pixel, Motorola, OnePlus), and every carrier handles that API slightly differently — and Verizon VoLTE configurations often skip it entirely.
VettedCalls bypasses that mess. We forward at the carrier level (where the rules are universal) instead of intercepting at the OS level (where every device is different). The result: same fast routing on every phone, no per-device debugging.
How it works on Android
- You install 3CX from Google Play (free, ~50MB)
- You tap the
.3cxconfigfile in your VettedCalls welcome email - 3CX provisions your VettedCalls extension automatically — no usernames or passwords
- You dial one carrier forwarding code (we send the right one for your carrier)
- Done. Spam screened, real callers ring 3CX with full caller context.
One-time carrier setup
After 3CX is active, dial your carrier's unconditional forwarding code (CFU) to point at your VettedCalls number. For AT&T/T-Mobile/most carriers: **21*YOUR_VETTEDCALLS_NUMBER#. For Verizon: *72YOUR_VETTEDCALLS_NUMBER. See our full carrier code list, or just tap the link in your welcome email — it pre-fills your dialer.
Samsung Galaxy users
Samsung is aggressive about killing background apps to save battery, which can cause 3CX to miss screened calls when your phone is idle. Add 3CX to Never sleeping apps (Settings → Battery → Background usage limits) during setup and you'll never see the issue.