<p>Note the word <em>normally</em> at the beginning of the sentence.  This isn't imposing a restriction but merely describing a common use case.</p>

<p>It's obviously useful to allow more than two outputs, and there's no particular reason to impose any arbitrary limit on the number.  I don't think such a limit was ever contemplated.</p>

<p>In any case, the whitepaper isn't considered to be an authoritative description of the protocol; that would be the reference client.  For instance, the whitepaper describes a scheme for reclaiming disk space that I don't believe was ever implemented (the "pruning" feature came much later and is somewhat different).</p>

CC BY-SA 3.0
2018-03-19T20:39:57.100Z
2018-03-19T20:39:57.100Z
Nate Eldredge
<p>The original <a href="https://bitcoin.org/bitcoin.pdf" rel="nofollow noreferrer">Bitcoin whitepaper</a> mentions that there can be at most two outputs:</p>

<blockquote>
  <p>Normally there will be either a single input from a larger previous
  transaction or multiple inputs combining smaller amounts, <strong>and at most</strong>
  <strong>two outputs</strong>: one for the payment, and one returning the change, if
  any, back to the sender.</p>
</blockquote>

<p>However, I see transactions like this:</p>

<p><a href="https://blockchain.info/tx/c18ff55d09c596ffbad30321719171c0d5b4d677d3554fc6ab3d12167ea8b9d6" rel="nofollow noreferrer">https://blockchain.info/tx/c18ff55d09c596ffbad30321719171c0d5b4d677d3554fc6ab3d12167ea8b9d6</a></p>

<p>that has many outputs.</p>

<p>Is this contradicting the Bitcoin paper or is there something I'm not getting?</p>

<transactions><output><whitepaper>
At most two outputs according to Bitcoin whitepaper. Multiple outputs in real transactions. How come?
Piero
# At most two outputs according to Bitcoin whitepaper. Multiple outputs in real transactions. How come?

(Asked by: username_0 on 2018-03-19)

The original [Bitcoin whitepaper](https://bitcoin.org/bitcoin.pdf) mentions that there can be at most two outputs:

> Normally there will be either a single input from a larger previous
> transaction or multiple inputs combining smaller amounts, **and at most**
> **two outputs**: one for the payment, and one returning the change, if
> any, back to the sender.

However, I see transactions like this:

<https://blockchain.info/tx/c18ff55d09c596ffbad30321719171c0d5b4d677d3554fc6ab3d12167ea8b9d6>

that has many outputs.

Is this contradicting the Bitcoin paper or is there something I'm not getting?

**Tags:** transactions, output, whitepaper


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## 1 answers

### Answer by username_1 on 2018-03-19. Score: 6 | Accepted answer

Note the word *normally* at the beginning of the sentence. This isn't imposing a restriction but merely describing a common use case.

It's obviously useful to allow more than two outputs, and there's no particular reason to impose any arbitrary limit on the number. I don't think such a limit was ever contemplated.

In any case, the whitepaper isn't considered to be an authoritative description of the protocol; that would be the reference client. For instance, the whitepaper describes a scheme for reclaiming disk space that I don't believe was ever implemented (the "pruning" feature came much later and is somewhat different).


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