Confirmation

When you send or receive bitcoin, a confirmation shows that your transaction has been officially recorded in a block on the blockchain. Each time a new block is added, your transaction gains another confirmation, making it harder to reverse or tamper with. Usually, after six confirmations, a transaction is considered permanently settled and extremely difficult to alter.

When a bitcoin transaction is first broadcast from a wallet, it doesn’t get confirmed right away. It enters the mempool, where it waits until miners include it in a block—usually prioritizing transactions with higher fees. Once a miner puts your transaction into a block, it leaves the mempool and is given its first confirmation.

One confirmation is typically enough to know your transaction is on the blockchain, but there’s still a slight risk. If the block your transaction is in gets replaced by another version of the chain (becoming an orphan block), your transaction goes back to pending status in the mempool. That’s why most users and services wait for at least two to six confirmations before considering the transaction secure.

It’s risky to accept payments with zero confirmations, because those transactions can still be changed or replaced by others paying higher fees—a practice called double spending. Waiting for multiple confirmations helps ensure your bitcoin transaction is final and secure.