<p>Yes, that's correct. A mainnet node would just see those transactions as invalid because the outputs they attempt to spend are not in its database. It would have no idea that there is some other network on which they are valid.</p>

CC BY-SA 3.0
2017-11-02T21:21:37.950Z
Thanks! I was wondering, and I felt like it was clicking once I understood inputs and outputs a little better, but I wasn't sure. Thanks for the answer!
jordaniac89
CC BY-SA 3.0
2017-11-02T18:25:23.387Z
2017-11-02T18:25:23.387Z
David Schwartz
<p>Indeed. When if you try to reference a <code>utxo</code> (unspent transaction output) from a previous transaction of the testnet in the mainnet, most likely there will be no match. </p>

<p>In case there was a match, you will need to prove that you can spend such output (by performing a digital signature normally), which is even less likely.</p>

CC BY-SA 3.0
2017-11-02T21:09:20.617Z
2017-11-02T21:09:20.617Z
sr_gi
<p>I've been reading up on how transactions actually work, but I'm not sure I understand how testnet bitcoins are kept from being spent on mainnet. My best understanding is that coins are actually references to transactions on the chain, so referencing a testnet transaction on the mainnet chain would not work. Is this correct?</p>

<transactions>
What keeps bitcoins mined in testnet from being used in mainnet?
jordaniac89
# What keeps bitcoins mined in testnet from being used in mainnet?

(Asked by: username_0 on 2017-11-02)

I've been reading up on how transactions actually work, but I'm not sure I understand how testnet bitcoins are kept from being spent on mainnet. My best understanding is that coins are actually references to transactions on the chain, so referencing a testnet transaction on the mainnet chain would not work. Is this correct?

**Tags:** transactions


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## 2 answers

### Answer by username_1 on 2017-11-02. Score: 2 | Accepted answer

Yes, that's correct. A mainnet node would just see those transactions as invalid because the outputs they attempt to spend are not in its database. It would have no idea that there is some other network on which they are valid.

> **Comments:**
> **username_0**: Thanks! I was wondering, and I felt like it was clicking once I understood inputs and outputs a little better, but I wasn't sure. Thanks for the answer!  

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### Answer by username_2 on 2017-11-02. Score: 1

Indeed. When if you try to reference a `utxo` (unspent transaction output) from a previous transaction of the testnet in the mainnet, most likely there will be no match.

In case there was a match, you will need to prove that you can spend such output (by performing a digital signature normally), which is even less likely.


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