KYC stands for know your customer. It is the identity check a firm runs before it pays you: usually a photo ID and a proof of address, sometimes a live selfie or a video check. The firm must confirm that the person trading the account and the person receiving the money are the same person.
KYC usually happens at the funded stage, not at sign-up, which is why it surprises traders. You can pass an evaluation and trade funded for weeks without hearing about it, and then find your first payout held until the check clears. A name mismatch between your account, your ID, and your payment method is the most common cause of a delay.
This matters because a failed or stalled check holds real money. A payout request cannot be approved while identity is unverified, and some firms will not release later payouts either until the first check is done.
The common trap is leaving KYC until payout day. We recommend completing it as soon as the firm offers it, and making sure the name on your payment method matches your ID exactly. Prop trading can cost you every fee you pay.