Six confirmations are typically recommended for a Bitcoin transaction to be considered secure.
A confirmation is added when a miner includes the transaction in a block. Each later block adds another confirmation, placing more proof-of-work behind the transaction and making a reversal increasingly difficult.
The number six is a widely used rule of thumb, not an absolute Bitcoin protocol requirement. Low-value payments may be accepted with fewer confirmations, while exchanges and high-value transactions may wait longer. Some services also treat an unconfirmed transaction as pending rather than final.
A common mix-up is thinking that six confirmations means six separate approvals. It actually means the transaction’s block plus five blocks built after it. Bitcoin blocks arrive about every 10 minutes on average, so six confirmations often takes roughly an hour, although block times vary. Confirmations reduce reorganization and double-spending risk but do not create mathematical finality.