From Kraken. This is so shite:

Wallet Verification for deposits from private wallets: If your private wallet deposit or withdrawal exceeds €1,000 in value, or if you’re using a new wallet address, you’ll be prompted to verify your wallet ownership.

Future Ease: Once a wallet is verified, future transactions with that same address won’t need further verification.

Seamless Verification Options

We’ve made the verification process straightforward and secure through one of two methods:

Self-Certification: Verify ownership with a simple one-click process and a quick 2FA security check.

Satoshi Test: Send a small transaction from your wallet to confirm ownership. We’ll guide you every step of the way.