Can you cancel BTC transaction with 1 confirmation?

[PaperWallet]

Hi,
I just wanted to know if you could cancel a BTC transaction after one confirmation (like sending it to yourself with a much higher fee?) Thank you!

[1714021479]

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[1714021479]

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[1714021479]

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[BlackHatCoiner]

No, since someone put it in a block it is irreversible.

As far as I know, you couldn't cancel it even if it had no confirmations. You could only reduce the fee so much that it would make any miner avoid it. Then, after 2 weeks it would disappear from the memory pool.

[Stedsm]

Sorry but it could only be possible with Replace by fee (RBF), that too if your transaction remains unconfirmed and as your transaction has 1 confirmation already (and unless a possible attack is made specially for you to reverse that block), it's impossible to get your coins back. Try asking the other party to give you your coins back as that's the only option seems to be left.

[RajaJudi]

Absolutely not. There is no way to reverse a transaction with at least 1 confirmation because apparently it have been appeared on the blockchain. And therefore, the process is irreversible. You can only make a double-spend transaction which make a transaction forever pending without receiving any confirmation

That is one of the power of the blockchain.

[Bitcoin577]

Hi,
I just wanted to know if you could cancel a BTC transaction after one confirmation (like sending it to yourself with a much higher fee?) Thank you!

Hopefully now you have reply of your question as mention its not reversible and you have only one option receiver send back to your funds  otherwise its gone.

[Gozie51]

If you are making a transaction, you need to be careful. With 1 confirmation, it means a miner is already processing it and can't be reversed. The fees have been accepted and it has been picked and confirmed to the blockchain. You need to read more on blockchain and bitcoin, then focus more on beginners and help section.

[btctaipei]

Have the person on the output end of this transaction return your fund is the only way. 
It is,  nearly impossible to do.

It is no different than people have send 500 BTC by mistake to unspent-able BTC addresses, if no one have the private key to spent your output address.

[PaperWallet]

Nice! That was really helpful! I got a lot of answers and now it's clear to me.
As far as I know though, I'm not sure I understand why. The blockchain is supposed to work like the majority of hash power wants it to be right? If I send one bitcoin from a wallet with only one BTC in it for a 30 cents fee, get one confirmation, and then send another transaction of 1 BTC to another wallet of mine with a 30 dollar fee, don't the other 5 miners process that transaction and confirm it? I will be reading more about this subject.

[hatshepsut93]

Nice! That was really helpful! I got a lot of answers and now it's clear to me.
As far as I know though, I'm not sure I understand why. The blockchain is supposed to work like the majority of hash power wants it to be right? If I send one bitcoin from a wallet with only one BTC in it for a 30 cents fee, get one confirmation, and then send another transaction of 1 BTC to another wallet of mine with a 30 dollar fee, don't the other 5 miners process that transaction and confirm it? I will be reading more about this subject.

When you'll try to broadcast a transaction that tries to spend the already spent outputs, it won't even propagate through the network, because nodes will reject it, as it's invalid. If you'll try to send it directly to the miner, no sane miner would include it in their block, because the whole block will be invalid and rejected by the rest of the network.

The only way to undo a confirmation is to mine a new chain with more total PoW than the current chain, starting from some block before the first confirmation occurred. To reliably do this, you'd need to control more than 50% of network's hashrate.

[Mugtaiya]

But then how does double spend work since the first transaction is already on it's way.

[Stedsm]

--snip--

I still believe it's a NO here because even if you double-spend, your only intention is to get your funds sent to the other party (or its destination address) quicker by letting your current (newly made) transaction get passed through (or in other words, get confirmed) against that same (old) transaction gets a confirmation and you can probably only change the speed of your transaction with fee increase through double-spend or increasing it through RBF, and not the destination of that transaction. Like I said before and as hatshepsut93 elaborated, you'll need to attack the Bitcoin network with more than 51% hashrate to be able to reverse some transactions but that's impossible.

[phreess]

Sorry but it could only be possible with Replace by fee (RBF), that too if your transaction remains unconfirmed and as your transaction has 1 confirmation already (and unless a possible attack is made specially for you to reverse that block), it's impossible to get your coins back. Try asking the other party to give you your coins back as that's the only option seems to be left.

The only option is to have 51%+ of hashing of the bitcoin network and hopefully, change that last block.

[Csmiami]

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I don't want to get very off-topic here, but couldn't RBF be done in the first 3 confirmations or so? I seem to recall reading something similar, about things to avoid (low number of confirmations) when dealing a face to face BTC-Fiat exchange....

[hosseinimr93]

I don't want to get very off-topic here, but couldn't RBF be done in the first 3 confirmations or so? I seem to recall reading something similar, about things to avoid (low number of confirmations) when dealing a face to face BTC-Fiat exchange....

It is always recommended to wait for a certain number of confirmations (usually 1-6 confirmations depending on the amount you receive). But that's not due to RBF feature. That's due to the probability of 51% attack. The more confirmations a transaction receives, the more difficult it is for the attacker to alter the transaction.

When you mark a transaction as RBF, you are telling miners and nodes that, as long as the transaction has not been confirmed, I may replace it with a new one paying higher fee.
So, even if a transaction has been marked as RBF, once it receives the first confirmation, it's no longer possible to be replaced.

[Serious475]

Hi,
I just wanted to know if you could cancel a BTC transaction after one confirmation (like sending it to yourself with a much higher fee?) Thank you!

I'm sorry but it is not possible even if you still have no confirmation because it is already transacted. If you really want to retrieve your bitcoin back to you then you have to communicate with the address you transacted so that they can send back your bitcoin but it will cost another transaction fee but atleast you get it back. If you accidentally sent it to an unknown address you cannot retrieve it back so we really have to be careful and think twice before we send our bitcoin.

[OcTradism]

Bitcoin transactions are irreversible and the cost of 51% attacks is expensive.

Bitcoin payments are irreversible
A Bitcoin transaction cannot be reversed, it can only be refunded by the person receiving the funds. This means you should take care to do business with people and organizations you know and trust, or who have an established reputation. For their part, businesses need to keep track of the payment requests they are displaying to their customers. Bitcoin can detect typos and usually won't let you send money to an invalid address by mistake, but it's best to have controls in place for additional safety and redundancy. Additional services might exist in the future to provide more choice and protection for both businesses and consumers.

To do attacks on network for 1 hour, the cost is more than $570k (estimation attack cost). One hour has more or less than 6 blocks (block interval is less or more than 10 minutes but the average block time is 10 minutes). In last 24 hours, the average time between blocks is 11 mins 37 secs


https://bitcoin.org/en/you-need-to-know
https://www.crypto51.app/coins/BTC.html
https://blockchair.com/bitcoin

[piebeyb]

it seems that it is difficult and I think it is impossible to do, how much money do you want to cancel it, is it so big that you want to cancel the transaction, I think when your transaction has been entered into a block and confirmed I think it is very difficult except you are a very important person

[pooya87]

you can not "cancel" any transaction whether they are confirmed or unconfirmed, since as soon as you broadcast a valid transaction there is no going back. however, you can "double spend" them which means spending the same inputs which could make the initial transaction invalid.

it costs nothing to double spend an unconfirmed transaction but it costs a lot to do it when it is confirmed.
you'll need at least 51% of the hashrate for a small possibility of doing it. current total hashrate is 118 EH/s or 118,000,000 TH/s. the best Antminer (S19 pro) produces 110 TH/s and costs $2387.00.
51% hashrate is currently 60,180,000 TH/s that requires 547,091 S19 Antminers with the total cost of $1.3 billion.
node that this does not even account for the power consumption of 547,091 miners running, their maintenance and cooling costs.

[mich]

it seems that it is difficult and I think it is impossible to do, how much money do you want to cancel it, is it so big that you want to cancel the transaction, I think when your transaction has been entered into a block and confirmed I think it is very difficult except you are a very important person

It doesnt matter the size of the transaction since others have already stated that its not possible to do what he is asking to do.
If this was possible there would be many chances to cheat or 'double spend'. 
If it was possible to do what he is talking about then Bitcoin would not be able to function in proper way.

[o_e_l_e_o]

current total hashrate is 118 EH/s or 118,000,000 TH/s. the best Antminer (S19 pro) produces 110 TH/s and costs $2387.00.
51% hashrate is currently 60,180,000 TH/s that requires 547,091 S19 Antminers with the total cost of $1.3 billion.

The 51% calculation you have made only applies if 51% of the existing hashrate was to turn evil and coordinate to attack the network. The 51% of the evil hashrate would out perform the remaining 49% of the honest hashrate.

In the situation of someone buying up Antminers or other new mining equipment to perform a 51% attack, we are assuming all the current hashrate remains honest. The attacker would need to buy enough hashrate to overcome 100% of the hashrate, so effectively 101%. This would give them 51% of the total combined (honest and evil) hashrate.

So the bottom line is it would be even more prohibitively expensive.

I'm sorry but it is not possible even if you still have no confirmation

It is absolutely possible to reverse transactions with zero confirmations, which is why they are not safe to accept.