Freeze authority

Freeze authority is a permission stored in a Solana token's mint. The address that holds it can freeze any token account, meaning any account in which someone holds that token. A frozen balance cannot be transferred or sold.

The permission has legitimate uses, for example in stablecoins issued by regulated companies that must be able to block funds on a court order. In a memecoin, though, there is no reason for the creator to keep it. An active freeze authority makes a honeypot possible: anyone can buy, but the creator freezes buyers' accounts before they can sell. Tokens from major launchpads usually start with this permission disabled. On EVM networks, blacklist functions in the contract code have a similar effect.