A key characteristic of blockchain is its immutability and transparency. This means that information on the network is almost impossible to edit or tamper with. Therefore, it is crucial to verify data before signing a transaction, as once an action is confirmed and added to a block, it cannot be canceled.

Is It Possible To Cancel A Blockchain Transaction?

Generally, cryptocurrency transactions cannot be edited or altered in any way. However, there is an opportunity to cancel a transaction before it is included in a block and enters the mempool waiting for its turn. Depending on the specific blockchain’s functionality and network load, the confirmation time for transactions can vary. For example, on the Bitcoin network, this can take up to 20 minutes. Transactions may also “pend” in the network due to the following reasons:

• Insufficient transaction fee
• Network congestion
• Attempting to use recently transferred digital assets
• Technical issues

Therefore, the only way to cancel a transaction on public blockchains like Bitcoin or Ethereum is to do so within the interval between signing and confirmation on the network.

How To Cancel A Blockchain Transaction?

Canceling a transaction can be difficult because it typically requires specialized knowledge and an understanding of the steps involved in resolving the issue. Some blockchains may have built-in mechanisms for altering transactions. However, in such cases, success depends on various factors, such as the operational status and network type. On private blockchains, canceling transactions might be easier because the network is centrally controlled, and administrators theoretically have the authority to cancel actions. Transactions can be canceled in the following ways:

• Using built-in mechanisms
• Sending a new transaction with identical details but higher fees to “push” the operation
• Contacting network administrators (for private blockchains) or experts

The earlier a user takes action to cancel a transaction, the higher the likelihood of success. If for some reason the cancellation is not timely, it may be worth directly contacting the recipient and requesting a refund of the assets. If cryptocurrency is transferred to an invalid address, funds may automatically return according to the protocol or be permanently lost.

Let’s see how to cancel transactions in different situations.

Cancelling a Transaction in MetaMask

In MetaMask wallet, there are two methods to cancel a transaction.

The first and simplest method is to use the built-in function.

To do this, in the transaction window, click the “Cancel” button, and then click “Submit” to sign the transaction, as shown in the screenshot below.

There is another method to cancel an unconfirmed transaction — sending a “null” transaction to your own address. This process is more complex.

First, note that every transaction has a unique identifier called a nonce. To cancel a pending transaction, you need to send another transaction to your own address. During this process, you must specify the nonce of the transaction you want to cancel.

However, this is considered an advanced feature, so you need to activate it in the advanced settings to manage nonces.

To set random numbers in MetaMask:

1. Click on the three dots in the top right corner, then select “Settings”:

1. Click”Advanced”:

1. Scroll down and enable the “Customize transaction nonce” option by finding it in the settings:

1. Thereafter, each transaction can set the nonce:

To “push” the desired operation, setting a higher gas fee is crucial. The MetaMask team recommends increasing the fee by at least 30% compared to previous transactions. Therefore, while the first method requires swift action, it’s definitely the better option!

Cancelling a Transaction in the Bitcoin Network

To cancel a transaction on the Bitcoin network, it typically involves checking the transaction status. This can be done using block explorers like Blockchain.com. Simply enter the transaction identifier (TxID):

If a transaction has already received at least one confirmation, attempting to cancel it no longer makes sense. However, if the confirmation count is zero, cancellation can be attempted.

Users can choose the strategy that best suits their needs.

• Fee Replacement (RBF) Protocol — Allows the original transaction to be replaced with a new one by increasing the transfer fee. However, not all wallets support RBF, so it’s advisable to check the parameters first.
• Double Spending — In this scenario, you can attempt to cancel a transaction by trying to transfer a similar amount of BTC to your own address. Ideally, miners will prioritize processing the last transaction. It’s worth noting that most nodes and crypto wallets have built-in safeguards against such actions.

About cancelling Ethereum transactions

In Ethereum, to cancel a transaction, the typical approach involves creating a new transaction with the same initial data but with an increased fee. This method can expedite

the processing of the new transaction, while the previous transaction will not be recorded on the blockchain.

Transactions can also be overwritten using the nonce. In this case, users initiate a new operation to their address and specify the nonce of the previous transaction.

In special cases, smart contracts can be used to cancel transactions. Some contracts include functionality to cancel operations if certain transaction conditions are not met.

Conclusion

Therefore, canceling a transaction requires prompt and decisive action. After all, most transactions in popular networks typically occur instantly and are irreversible.

This blockchain approach aims to maintain and enhance the security of decentralized networks.

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