I encountered 'millisatoshi' (msat) while browsing Lightning Network..., see screenshoot below:

Taken from https://lnmainnet.gaben.win/

And subsequently I found it mentioned here:


Obviously, I am curious... I thought satoshi is the smallest unit?


1 Answer 1


It's not a mistake, it's literally a thousandth of a satoshi. A satoshi is the smallest unit for bitcoin, but lightning can transact with even smaller units while channels are open. The amount is rounded down to the nearest satoshi when the channel is closed and broadcast to the blockchain to adhere to bitcoin's limit.

  • Since the satoshis commitment transactions are always necesserily atomic, are fractional satosh just some kind of unenforcable gentlemens agreement? Commented Jun 2 at 9:58
  • 1
    > Now, what happens if the fee is very low? Let's say the base fee is zero and the fee rate is 25 PPM, and you route 10,000 satoshis. The fee would be 0.25 satoshis. Since the smallest amount in Bitcoin is 1 satoshi, you can't earn and be paid 0.25 satoshis (or 250 milli satoshis). However, the money is not lost. If you were to route four such transactions through the same channel, the partial satoshi earnings will add up, and you will earn a single 1 satoshi (1,000 milli satoshis) eventually. lightningnetwork.plus/posts/568
    – northben
    Commented Jun 5 at 18:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.