Coin control
Also · UTXO management · Labels · Toxic change
Coin control is choosing by hand which UTXOs a transaction spends, instead of letting the wallet pick. It keeps coins with different histories apart and keeps fees in check.
By default, a wallet selects which of your UTXOs to spend based on its own rules, often to minimise fees. In doing so it can combine coins bought with your passport at an exchange, coins mined at home and coins received from a friend, publicly linking all 3 histories in 1 transaction. Coin control hands that choice back to you.
It works with labels. Tag each UTXO with where it came from, and you can pay a merchant from the coins you are willing to associate with that purchase, consolidate only coins that already share a history, and quarantine the change left over from a sensitive transaction, sometimes called toxic change. It is the daily discipline that turns privacy from a tool into a habit.
In French · Coin control