Pre-ring AI scam shield: why your UK business phone should drop scam calls before it rings

UK businesses got 33 million unsolicited / scam calls in 2025 according to Ofcom. Most spam-filter products run after the call rings — which means your receptionist or sales agent has already been interrupted. We do it differently.

How the Silux Call scam shield works

1. Inbound call hits the dialplan macro
2. silux-scam-shield
3. .
4. A loopback call goes to the backend within 0.2 s with the caller-ID and called DDI.
5. The shield evaluates tenant rules + Silux global block list + AI heuristics (anonymous CLI, all-zeros number, mismatched country code, known carrier signatures).
6. A score above 0.6 returns "block" → the call is hung up with SIP 603
7. before
8. the phone rings.

What gets blocked

• Spoofed HMRC / DVLA "tax owed" scams (rotating UK 0800 ranges).
• Royal Mail / DPD / Evri parcel-fee scams (overseas CLI, UK destination).
• Microsoft / BT "your account is compromised" wardialers.
• Anonymous / "withheld" calls if your tenant policy includes them.

Tenant control

Add your own block patterns at Dashboard → Scam Shield. Patterns support glob (+44800111111*), and actions are block / voicemail / challenge / allow. The hit log shows the 100 most recent screened calls with the rule that fired.

Who else ships this?

Of the 19 providers in our comparison matrix, exactly zero ship pre-ring AI scam screening. Everyone else either blocks after the call rings, or sells it as a £/seat/month add-on. We bundle it on Plus and above.