Crypto glossary
Coin control
Coin control is a wallet feature that lets you choose which UTXOs a Bitcoin transaction spends, to protect privacy, manage fees and avoid tainted coins.
By default, wallets select inputs automatically using an algorithm that tries to minimise fees or change. Coin control exposes the list of individual outputs, often with labels, and lets the user pick which ones to spend, freeze outputs that should never be touched, and decide where change goes. Desktop wallets such as Sparrow and Bitcoin Core, and many hardware wallet companions, offer it.
The main reason is privacy. Spending outputs from different sources together tells observers they share an owner, so users keep coins bought on a KYC exchange separate from those received privately, or keep CoinJoin outputs apart from non-mixed ones. Coin control also helps with fees, letting users spend a single large output instead of many small ones, and with dust attacks, by freezing suspicious tiny deposits.
The feature demands discipline and some understanding of UTXOs; careless selection can leak more information than automatic selection. Labels are local to the wallet unless exported. Account-based chains like Ethereum have no equivalent, because balances are not split into separate outputs.
Example
A user freezes a 546-sat output that appeared unexpectedly in their wallet, suspecting a dusting attack, and selects only their own savings outputs when paying a supplier.