<p>Correct. <code>tx0</code> is removed, and <code>tx0child</code> is &quot;invalid&quot; because it spends a UTXO that does not exist in the current chain or mempool. This could change in the future with package RBF and package relay if <code>tx0 + tx0child</code> are submitted as a package.</p>
<p>In this scenario, if the goal for <code>tx0child</code> was to fee-bump the original payment and RBF is possible, it probably makes more sense to just create another RBF to replace <code>tx1</code>.</p>

CC BY-SA 4.0
2022-06-24T14:19:26.140Z
2022-06-24T14:19:26.140Z
glozow
<p>Let's say I broadcast a transaction <code>tx0</code> signaling RBF replaceability. Later on, send another transaction <code>tx1</code> that spends the same inputs of <code>tx0</code>, but this time with higher fees.</p>
<p>In this case, tx0 is <strong>removed</strong> from mempool right? so what if then I try to send a child transaction <code>tx0child</code> that forms a more profitable CPFP than <code>tx1</code> alone? But without the context of <strong>removed</strong> parent (<code>tx0</code>) this CPFP cannot work then, although it's more profitable?</p>

<mempool><replace-by-fee><child-pays-for-parent><package-relay>
A question about CPFP relaying policy
Burak
# A question about CPFP relaying policy

(Asked by: username_0 on 2021-05-31)

Let's say I broadcast a transaction `tx0` signaling RBF replaceability. Later on, send another transaction `tx1` that spends the same inputs of `tx0`, but this time with higher fees.

In this case, tx0 is **removed** from mempool right? so what if then I try to send a child transaction `tx0child` that forms a more profitable CPFP than `tx1` alone? But without the context of **removed** parent (`tx0`) this CPFP cannot work then, although it's more profitable?

**Tags:** mempool, replace-by-fee, child-pays-for-parent, package-relay


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## 1 answers

### Answer by username_1 on 2022-06-24. Score: 5 | Accepted answer

Correct. `tx0` is removed, and `tx0child` is "invalid" because it spends a UTXO that does not exist in the current chain or mempool. This could change in the future with package RBF and package relay if `tx0 + tx0child` are submitted as a package.

In this scenario, if the goal for `tx0child` was to fee-bump the original payment and RBF is possible, it probably makes more sense to just create another RBF to replace `tx1`.


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