KYC stands for Know Your Customer and refers to the process that prop firms use to verify the identity of traders before issuing a funded account or processing a payout. Verification typically involves submitting a government-issued ID, proof of address, and, in many cases, a face check to confirm the documents belong to the person submitting them.
KYC exists to confirm who the firm is paying and to prevent fraud where a single individual tries to operate multiple accounts under different identities.