<p>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 <a href="https://github.com/lightningnetwork/lnd/blob/master/lnwire/msat.go#L22-L24" rel="nofollow noreferrer">rounded down</a> to the nearest satoshi when the channel is closed and broadcast to the blockchain to adhere to bitcoin's limit.</p>

CC BY-SA 4.0
2024-06-02T09:58:54.610Z
Since the satoshis commitment transactions are always necesserily atomic, are fractional satosh just some kind of unenforcable gentlemens agreement?
user2741831
CC BY-SA 4.0
2024-06-05T18:21:21.620Z
> 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.

https://lightningnetwork.plus/posts/568
northben
CC BY-SA 4.0
2018-01-28T11:18:49.230Z
2022-12-30T20:51:40.337Z
2022-12-30T20:51:40.337Z
meshcollider
<p>I encountered 'millisatoshi' (msat) while browsing Lightning Network..., see screenshoot below:</p>

<p><a href="https://i.sstatic.net/prrXi.png" rel="noreferrer"><img src="https://i.sstatic.net/prrXi.png" alt="Taken from https://lnmainnet.gaben.win/"></a></p>

<p>And subsequently I found it mentioned here: </p>

<p><a href="https://github.com/ElementsProject/lightning/blob/master/README.md#sending-and-receiving-payments" rel="noreferrer">https://github.com/ElementsProject/lightning/blob/master/README.md#sending-and-receiving-payments</a></p>

<p>Obviously, I am curious... I thought satoshi is the smallest unit?</p>

<lightning-network><satoshi><divisibility>
What is a millisatoshi? I thought satoshi is the smallest unit?
Rosdi Kasim
# What is a millisatoshi? I thought satoshi is the smallest unit?

(Asked by: username_0 on 2018-01-28)

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

[![Taken from https://lnmainnet.gaben.win/](https://i.sstatic.net/prrXi.png)](https://i.sstatic.net/prrXi.png)

And subsequently I found it mentioned here:

<https://github.com/ElementsProject/lightning/blob/master/README.md#sending-and-receiving-payments>

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

**Tags:** lightning-network, satoshi, divisibility


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## 1 answers

### Answer by username_1 on 2018-01-28. Score: 13 | Accepted answer

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](https://github.com/lightningnetwork/lnd/blob/master/lnwire/msat.go#L22-L24) to the nearest satoshi when the channel is closed and broadcast to the blockchain to adhere to bitcoin's limit.

> **Comments:**
> **username_2**: Since the satoshis commitment transactions are always necesserily atomic, are fractional satosh just some kind of unenforcable gentlemens agreement?  
> **username_3**: > 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.  https://lightningnetwork.plus/posts/568  

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