Stuck Bitcoin Transactions: Can CPFP Help?

Hey, I need some help here. I’ve got some coins stuck since April ‘23 in a Bitcoin Core wallet. They only paid 1 sat/vb and don’t signal RBF, so I can’t bump the fees through the GUI. Any way to fix this without diving into the command line? Thanks.

You might be able to sort it out by enabling unconfirmed change in the settings, although not sure if it will apply to outputs from other wallets. If that doesn’t work, you could generate a PSBT transaction in Electrum by importing your BTC address from Core. Then create a transaction and send it, either to another address or back to yourself. Save it as.PSBT, sign it, and broadcast from Core. I haven’t tried it myself, but I think it should work.

Check out importing your private keys to Electrum. There’s a guide on getting a stuck low-fee transaction unstuck by using CPFP with Electrum.

Even if you have opt-in RBF, you still can’t use the "Increase transaction fee" option for those transactions since you’re the receiver. CPFP is the way to go, but the wallet in Bitcoin Core can’t do it directly. You’ll need to use commands and calculate amounts and fees. Or just follow BitMaxz’s idea: import the address to Electrum, create a CPFP unsigned transaction, export the PSBT, then import it to Core and broadcast.

That won’t work, though. Bitcoin Core doesn’t let you send unconfirmed incoming coins through the GUI. But I’ve used CPFP from Core before by exporting the private key, importing it into Electrum, and making the transaction. But since it’s been a year, that transaction won’t show in Electrum.

Yeah, as mentioned by LoyceV, it’s not possible, unfortunately. But I found a way to resolve this. It was pretty straightforward. Thanks!

Yeah, dealing with private keys can be pretty risky. Thankfully, I managed to fix this without touching them. Appreciate the resources!

How’s that even possible? You’re talking about a transaction from a year ago at 1 sat/vbyte, while the purging limit is like 6.21 sat/vbyte.

I pointed Electrum to my node with a non-default mempool, so it’s not purging anything right now. Otherwise, I probably wouldn’t even see those transactions. Even if mempool.space shows them as only a few weeks or months old, who knows.

Can you clarify this scenario? When you replied, the purging limit was around 6.21 sat/vbyte, and now it’s down to 4.04 sat/vbyte. If I have a transaction in the mempool at 3.9 sats/vbyte, does it get purged immediately if the limit drops below that, or does it take time?

Under default settings, that transaction should drop right away. But every node can have its own settings. That’s how mempool.space tracks a total of "1.10 GB / 300 MB" of mempool data. They probably keep everything. Just because a transaction is accepted by a certain mempool doesn’t mean a miner will include it in a block.

You can keep broadcasting your transaction as much as you want. The key question is: do the peers drop it immediately because it’s below their purge limit? Will it ever reach mempool.space? You might get lucky if some peers have a bigger mempool with a lower purge limit. Statistically, your transaction might get seen by mempool.space, but I wouldn’t bet on it unless you can verify.

Haven’t heard about any public Bitcoin node addresses for mempool.space, but they do share their Lightning node addresses.