One-sentence answer
A transaction gets its first confirmation when it enters a valid block; each later valid block on that chain adds another confirmation.Broadcast is not confirmation
After a wallet sends a transaction, it propagates through the peer-to-peer network and may enter many nodes’ mempools. Other people can see it before it is in a block.
Nodes still check signatures and available funds. Wide propagation does not make an invalid transaction valid.
Accumulation starts inside a block
A miner includes the transaction in a valid block. Once nodes accept it, the transaction is usually described as having one confirmation. Every valid block built afterward increases the work needed to rewrite that history.
A confirmation is not a certificate from a central institution. It is depth within a chain of accumulated work.
How many confirmations are enough?
There is no single number for every payment. Small payments, reversible services, and high-value irreversible delivery have different risks. Recipients choose policies based on amount, counterparty, other protections, and waiting cost.
BTCVisual does not provide transaction advice; this page explains the mechanism itself.
Three things to remember
- ✓A propagated transaction has not necessarily entered a block.
- ✓Confirmations measure depth in a valid chain.
- ✓A waiting threshold is contextual, not one protocol-mandated number for everyone.
A common follow-up
Do more confirmations make a transaction absolutely irreversible?
More confirmations rapidly increase the cost of a reorganization, but “absolute” is not technically precise. Risk depends on accumulated work, network conditions, and context.
Primary sources
Primary sources
These links lead to protocol material, developer documentation, or open-source code—not trading services.