How many confirmations does each blockchain need before a swap completes

05 September 2026

The number of confirmations required varies by blockchain, and the exchanger sets these thresholds based on each chain's block time and finality guarantees. For Bitcoin, the standard is 3 confirmations; for Ethereum, 12 confirmations; for Litecoin, 6; for Dogecoin, 20; and for most proof-of-stake chains like Solana or Polygon, a single confirmation suffices.

These numbers are not arbitrary. They reflect a trade-off between speed and security. A confirmation is a block that includes your transaction and is built upon by subsequent blocks. The more confirmations, the harder it becomes for an attacker to reverse the transaction by reorganising the chain. The exchanger chooses thresholds that make reversal economically impractical given the chain's mining power or staked value.

Bitcoin's 3-confirmation rule is conservative. With Bitcoin's 10-minute average block time, 3 blocks means roughly 30 minutes before the swap proceeds. An attacker would need to control more hashrate than the honest network for those three blocks - a costly proposition for anything but extremely large transactions. Some services require 6 confirmations for high-value swaps; the exchanger here uses 3 as a practical minimum.

Ethereum's 12 confirmations look high, but blocks come every 12-15 seconds. That's about 2.5 to 3 minutes total waiting. The logic differs from Bitcoin. Ethereum uses a finality mechanism called Gasper; after 12 blocks, the chain reaches "economic finality" - reversing would require burning enormous amounts of staking/slashing-conditions-and-penalties/">staked ETH. For simple Ethereum transfers, some exchangers accept fewer, but for cross-chain swaps the full 12 are standard.

Litecoin and Dogecoin both derive from Bitcoin's codebase but have different block times. Litecoin blocks arrive every 2.5 minutes; 6 confirmations take about 15 minutes. Dogecoin's blocks come each minute, but the chain has lower overall security; 20 confirmations (20 minutes) compensates for that. The exchanger applies a higher threshold to Dogecoin because the chain has experienced reorganisations in the past.

For blockchains with instant finality - typically proof-of-stake systems where validators finalise blocks as part of the consensus protocol - one confirmation is enough. Solana's tower BFT, Polygon's checkpoint system, and Binance Smart Chain's rapid finality all mean the first block including your transaction is effectively permanent. The exchanger treats these as settled immediately.

It matters because the swap cannot proceed until the incoming transaction is confirmed. The exchanger watches the source chain for your deposit. It waits for the required confirmations. Only then does it broadcast the outgoing transaction on the destination chain. If it acted too soon, a chain reorganisation could orphan your deposit, and the exchanger would lose money. If it waited forever, you would abandon the swap.

You do not need to calculate these numbers yourself. The swap interface displays a status like "Waiting for 3/3 confirmations" or "1/12 confirmations". The page from the hub, "Swapping crypto across chains", explains the overall flow these confirmations fit into - how the exchanger matches your deposit to your destination address without holding your funds in a centralised account.

One nuance: some chains require confirmations for the memo or destination tag as well. If you forget it, the swap stalls regardless of confirmations. That is covered in the sibling page about destination tags. The confirmation count only matters once the transaction includes the correct tag.

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