What a confirmation is
When you broadcast a transaction it waits in the network's pool of pending transactions (the mempool). When a miner or validator includes it in a block, it has one confirmation. Each new block built on top adds another. Reversing a transaction would require rewriting every block above it, which becomes practically impossible as the count grows.
Why more is safer
On a proof-of-work chain, an attacker would need to out-mine the whole honest network to rewrite blocks. With one confirmation that's conceivable for small networks; with six or more it's effectively out of reach for large ones. On smaller coins with less total mining power, waiting for more confirmations is more prudent.
How many should you wait for?
There's no universal number. It depends on:
- Block time — Litecoin blocks arrive about every 2.5 minutes, Dogecoin about every minute, Bitcoin about every 10, so "6 confirmations" means very different waits
- Amount — a small payment may be fine at 1–3; a large one deserves more
- Network strength — smaller-hashrate coins carry more reorg risk
Services publish their own thresholds for crediting deposits; follow theirs.
Confirmed doesn't mean correct
A confirmation proves the transaction is on the chain — not that you sent it to the right person or address. Verify recipients before you send; confirmations can't fix mistakes.
Reading a pending transaction
If a transaction sits at zero confirmations, look at its fee relative to what others are paying right now. A very low fee explains most long waits. Don't re-send the same payment while the first is still pending — you could end up paying twice. Wait, check the transaction in a block explorer, and act only once you can see whether it was dropped or is simply queued.