What is CPF?

CPF (Cadastro de Pessoas Físicas) is Brazil’s individual taxpayer identifier—an 11‑digit number used across finance, employment, and public services. In onboarding and KYC flows, CPF is both a key and a trap: it unlocks authoritative checks, but it also appears in leaks and scams, so you must validate structure, provenance, and ownership—not just format.

Practical steps: verify CPF checksum and status against authoritative sources; reconcile name, DOB, and mother’s name where available; and detect reuse across many “different” applicants. Watch for synthetic blends—real CPF combined with fabricated addresses or phones—and for enrollment bursts from shared devices or ASNs.

Privacy and compliance matter: collect CPF only when necessary, protect it in transit and at rest, and restrict access by role. Refresh on triggers—address or phone changes, high‑risk product upgrades, suspicious behavior.

Use CPF as one signal in a broader proofing stack: document authenticity, selfie match, and liveness to ensure the person presenting the number is its rightful holder (identity verification). When residency proof is needed for benefits or risk models, pair with proof of address. CPF done right reduces friction for good customers—and raises the bar for fraudsters.