can you reverse or cancel a bitcoin transaction?

[Linkkoin]

Personally, I do not believe that bitcoin transaction can be cancelled after it's sent.
My assumption is that ...miners start the mining of bitcoin immediately it's the sent button is clicked.
There's no way of knowing which miner so as to signify to the person to cancel the transaction or reverse it.
It's just too complicated.

I was thinking of what is the one drawback which bitcoin has ?  The only drawback is that if you sent the amount to wrong address or wrong amount to the right address even, the process cannot be reversed and therefore one should be extra careful when sending bitcoins to any address.

This is why unfortunately some binary options moved to cryptocurrencies, damaging the reputation of the whole crypto community.

[kalstarzz]

as long as I use Bitcoin I have never found a way to cancel a transaction, and I don't think we can do it, what I know is that there will never be a double transaction in Bitcoin.

[awawo]

It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.

You can't cancel or revert a transaction.

However, there are a couple "tricks" you can pull while a transaction is UNCONFIRMED.

For example, you can create a (very) low-fee transaction, and broadcast it to as little nodes as humanly possible. Then, create a new transaction, using the same unspent outputs as input but funding a completely different address as the first transaction. You can create this secondary transaction with a much higher fee and broadcast it to as many nodes as possible.
If you do this, there is a decent chance a miner will put the second transaction into the block he's currently working on instead of the first one. And once one of those transactions ends up in a valid, broadcasted block that's been added to the blockchain, the other transaction is automatically "voided". It's using unspent outputs that are no longer in the UTXO set, so the unconfirmed tx becomes invalid.

If you're setting up a service, it's always a good idear to wait for at least 1 confirmation before sending goods or services. For expensive products, you might even chose to wait 3+ confirmations ( 6+ for the really paranoid shop owners). Once a transaction has a couple of confirmations, there is no way of cancelling or reversing it.

Very clear analysis I know this will work effectively, and my question is what if you have balance on your account after the second transactions have been achieved that can found the amount that the first transaction demands what will happen in this situation?

[Artemis3]

It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.

That is not a cancel, and is not a reverse, that is just what you yourself said: A double spend. Only one may enter the blockchain, and that obviously is the one paying the higher fee, even when broadcasted later. Your window of opportunity could be a a small as the time remaining to find the next block, so its not even guaranteed you would succeed.

Unfortunately the likely people making the mistake probably didn't even bother lowering the tx fee shrinking their chance.

Moral of the story: triple check where you send your coins to.

You CANNOT reverse or cancel a tx.

[mocacinno]

--snip--

I don't know how this work but i am tested for 2 transaction and after 3 hours i get back , my transaction replaced with 0.0008 BTC amount in my wallet
i think here your destination wallet is not correct

So, is it your scamsite, or are you just a payed shill? What this site portaits is theoretical impossible, so if you keep insisting something theorethical imposible has happened, the only logical conclusion is that you're trying to scam the users of this forum...

[tunapa]

i wish it could have been possible to do. but any spent bitcoin cannot be cancelled. thats why it is always advisable to check well and be sure of where you are sending bitcoins to before clicking send button. in case of making payment in a store for good purchased, this would have been stated clearly to be mindful of sending bitcoins to wrong address or QR code scanning can be used this will avoid any issues of sending to wrong address.

[fortunecrypto]

It has been said sometimes that a Bitcoin transaction can be cancelled or reversed using for example double-spend.
Is it still possible? If Yes, how? If No, Why?
Especially when you sell services and goods and accept Bitcoin payment, you are worried about this.
So it should be a good idea to discuss this topic.

You can't cancel or revert a transaction.

However, there are a couple "tricks" you can pull while a transaction is UNCONFIRMED.

For example, you can create a (very) low-fee transaction, and broadcast it to as little nodes as humanly possible. Then, create a new transaction, using the same unspent outputs as input but funding a completely different address as the first transaction. You can create this secondary transaction with a much higher fee and broadcast it to as many nodes as possible.
If you do this, there is a decent chance a miner will put the second transaction into the block he's currently working on instead of the first one. And once one of those transactions ends up in a valid, broadcasted block that's been added to the blockchain, the other transaction is automatically "voided". It's using unspent outputs that are no longer in the UTXO set, so the unconfirmed tx becomes invalid.

If you're setting up a service, it's always a good idear to wait for at least 1 confirmation before sending goods or services. For expensive products, you might even chose to wait 3+ confirmations ( 6+ for the really paranoid shop owners). Once a transaction has a couple of confirmations, there is no way of cancelling or reversing it.

Merit you for a great explanation, I have not encountered a transaction where I could wish or plan to reverse, but this one is going to be a big help if ever I have I encounter something like this, this is a big help for those selling goods and offering services.

[lyks15]

Bitcoin transactions cannot be reverse or cancel. This is online transaction and when you pay bitcoin using online it is straight to the sellers system especially when you transact at the big business stablishment or company that already upgrade their system  but when you are have a bitcoin transactions to a person to person buy and selling  I think there is possibility that you may reverse your money by sending back your bitcoin.

[Kakmakr]

Double spending and reversing a transaction is actually two separate things. In a double spend you can spend the same bitcoin more than once. <This can happen if you manage to gain more than 51% of the total hashing power of all the mining that are done>  https://www.blockchain.com/en/charts/hash-rate  <Pretty expensive way to perform a double spend  >

Reversing a transaction is similar to a chargeback with a credit card and this is not possible with Bitcoin under normal circumstances, when say 1 or more confirmations has been received. <Something that most merchants love about Bitcoin> 

[Ojengonggu]

we already know that all the bitcoin transactions that have been running, it is impossible to cancel because at that time the data block has begun to be resolved and this is not a transaction like what happens to cash that we can withdraw, so be careful in making wise transactions every time we place an order for bitcoin transactions, we know the risk

[judeafante]

There is no way to do that, that is why you need to transact to people you trust or company that has a good buyer good rating, this is an advantages and disadvantages of blockchain and Bitcoin it's decentralized like PayPal or other online company where they can reverse the transaction for you if there is error in sending it.

[Nasty23]

we already know that all the bitcoin transactions that have been running, it is impossible to cancel because at that time the data block has begun to be resolved and this is not a transaction like what happens to cash that we can withdraw, so be careful in making wise transactions every time we place an order for bitcoin transactions, we know the risk

I agree with you, that it is impossible to cancel or reverse every bitcoin transaction that's why it is very important for us to study it first before doing any transactions so that we would not regret for what we have been done but we will receive a benefits from it because in that way we can use and transact any amount of money wherever we are.

[levyashin]

If that was possible i don't think bitcoin will have the popularity right now. It is what it should be also. I mean if you do a money transfer can you reverse that?

[aioc]

This is one of Bitcoin's strongest and most liked feature, without this feature and decentralization, Bitcoin will not be this popular, so be sure that before you send that coins, you are 100% sure that you want to do that unless you are sending it to a company which offers reversal.

[bhabygrim]

I think once it is already sent or the transaction is already out,
There is nothing that we couldn't do with it but to wait till it is confirmed.
We couldn't reverse or cancel a Bitcoin transaction once it is made.

[Ucy]

Not possible as far as I can tell . Though I have read couple of suggestions about making this possible only on side chain or with other applications while leaving the main chain irreversible. If you understand the idea behind irreversible transactions, you wouldn't worry too much about it.
Only unconfirmed transactions can be reversed I think.

[jerrison]

bitcoin transaction and blockchain technology in general is known for its irreversible and un-cancellable  transaction feature so when a transaction is initiated in the blockchain space, it does not get cancelled or reversed as the technology was not designed in that light

[minersday]

Once you click on the send button, your transaction can't not be reversed or cancelled. I wish this aspect of Bitcoin could be upgrade to help people cancel their transaction request if the transactions has not yet been confirmed by the blockchain network. Such upgrade is going to transform the whole nature of the bitcoin ecosystem.

[santiPOGI]

Think before you click as everyone says.
Always to just not triple check the transaction before sending it as it is permanent and cannot be undone.
Blockchain technology is great, once done it will be history!

[BennyK]

Verified of confirmed transaction cannot be reversed because it is already mined and added to the Block. This is why several attempts has been made on the forum to create awareness on the necessity to double-check and if possible check as many times as possible the amount to be sent and the receiving address before sending.