What is KYC (Know Your Customer)?
Identity verification requirements that regulated financial services must collect from their users. Including most Bitcoin exchanges. Required by law in most countries as an anti-money laundering measure.
Why It Matters
KYC is the interface between Bitcoin and traditional finance. Bitcoin is pseudonymous. Governments aren't. They require exchanges to verify customer identity to comply with anti-money laundering laws. KYC creates a permanent link between your identity and your exchange account.
That tradeoff lets you buy bitcoin with dollars and withdraw to your bank. It also gives governments a surveillance point. For people who want maximum privacy, KYC is the cost of access to traditional finance. Non-KYC options exist (peer-to-peer exchanges, in-person trades) but they're less convenient and have less liquidity. Most buyers accept KYC for the convenience of using a major exchange that handles the fiat side and custodies coins until they decide to move them off.
How It Works
You create an account on a regulated exchange. Provide your legal name, address, date of birth, and other identifying information. The exchange verifies this through background checks, government ID scans, and sometimes video verification. Once verified, you're assigned a KYC tier that determines how much you can buy.
Your identity is stored on the exchange's servers. The record links you to the bitcoin you bought there. Move that bitcoin off the exchange to a non-custodial wallet and you break the direct link. Your subsequent on-chain transactions are pseudonymous. Pseudonymous. Not anonymous. The exchange still has your initial purchase records, and governments can subpoena them at any time to reconstruct the chain of custody from your first KYC-verified purchase forward through every wallet you've moved coins into.
A worked example. Most major exchanges have three KYC tiers. Tier 1 requires email and phone verification, with weekly purchase limits around $25,000. Tier 2 requires a government ID and photo verification, raising the limit to roughly $50,000 per week. Tier 3 requires proof of address and source of funds, with no fixed cap. Move bitcoin off the exchange to your own self-custody wallet and the on-chain trail continues to be visible on the public blockchain, just no longer obviously tied to your name unless someone connects the dots through the original exchange record.