<p>The order must be causal. Most blocks today have outputs that were created earlier in the block. </p>

CC BY-SA 4.0
2019-02-28T23:16:47.630Z
2019-02-28T23:16:47.630Z
G. Maxwell
<p>Block 546 is the first time a (actually two) transaction spends the UTXO of a transaction from the same block.</p>

<p>Is the order important? (The transaction that generates the UTXO has to appear before in the block than the transaction that spends it)</p>

<p>Is it still possible today?</p>

CC BY-SA 4.0
2019-02-28T23:43:43.550Z
Maybe this can help: https://bitcoin.stackexchange.com/questions/50576/can-transaction-inputs-reference-outputs-of-pending-transactions
CryptoSmart
<block><utxo>
Spending UTXO from same block
Kevin P
# Spending UTXO from same block

(Asked by: username_0 on 2019-02-28)

Block 546 is the first time a (actually two) transaction spends the UTXO of a transaction from the same block.

Is the order important? (The transaction that generates the UTXO has to appear before in the block than the transaction that spends it)

Is it still possible today?

**Tags:** block, utxo

> **Comments:**
> **username_1**: Maybe this can help: https://bitcoin.stackexchange.com/questions/50576/can-transaction-inputs-reference-outputs-of-pending-transactions  

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## 1 answers

### Answer by username_2 on 2019-02-28. Score: 5 | Accepted answer

The order must be causal. Most blocks today have outputs that were created earlier in the block.


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