Skip to main contentBlockchain confirmations secure transactions and ensure finality on a
blockchain. When you build on Circle’s platform, understanding confirmations
helps you balance speed with the risk of blockchain reorganizations (reorgs).
What are blockchain confirmations?
When you submit a transaction to a blockchain, it starts in a pending state. The
network must include it in a block and validate it before it counts as
confirmed. Each new block added after that makes the transaction harder to
reverse.
A confirmation number is the number of blocks that must follow a
transaction’s block before it is final. Once the confirmation number is reached,
the transaction can’t be reversed.
Why confirmations matter
Without enough confirmations, transactions are at risk of reorgs. A reorg
happens when validators discard recent blocks and replace them with new ones,
rewriting part of the blockchain’s history. This can reverse transactions that
appeared settled.
Each extra confirmation makes a reorg less likely. Because blockchains differ in
design, block times, and consensus, the number of confirmations needed varies by
blockchain.
Confirmation numbers by product
Each Circle product sets its own confirmation numbers for the blockchains it
supports. For details, see:
