Voice Fraud & Compliance Wiki

    SIP & Network

    E.164

    The ITU standard number format that gives every phone number a globally unique representation: a plus sign, country code, and subscriber number.

    An E.164 number is at most 15 digits, written as +15551234567. Normalizing every number to E.164 on ingress removes an entire class of bugs where the same number appears in several formats.

    Fraud controls, blocklists, and DNO lists are only reliable when every comparison happens against a single canonical format.

    Why it matters to carriers

    Inconsistent number formatting is a silent cause of blocklist misses — the number was on the list, just written differently.

    Handling e.164 on your own switch

    SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.