How to Cancel a Bitcoin Transaction if it is Unconfirmed?

A Bitcoin transaction needs to be verified by the Bitcoin network before it can be completed. This verification is done by so-called Bitcoin miners, which are actually just powerful computers that all run Bitcoin’s code and store its blockchain. When someone sends a Bitcoin to someone else, the transaction is broadcast to the network and included in a block by the miners. Once the transaction is in a block, it is considered confirmed and the recipient can spend the Bitcoins. However, if the transaction is not included in a block, it is considered unconfirmed and stays in the network as an unconfirmed transaction. Most Bitcoin wallets will not let you spend unconfirmed transactions, so you will need to wait for a miner to include your transaction in a block before it can be completed.

Why do Bitcoin Transactions Remain Unconfirmed?

There are several reasons for the pending status of a bitcoin transaction. There are two types of transactions on the Bitcoin Network:

1. Processing Transactions: These transactions are incomplete but they are being processed on the network. There are several reasons for the pending status of the processing transactions on the bitcoin network:

1. Low-fee transaction: The most common reason for an unconfirmed transaction is that it is a low-fee transaction. Low-fee transactions are often not included in blocks by miners because it is not profitable for them to do so. When a transaction is created, it is not immediately broadcast to the network. As a result, these transactions can remain unconfirmed for a long time. Bitcoin transactions may remain unconfirmed due to lower transaction fees because miners may prioritize other transactions that have higher fees. This means that the transaction with the lower fee may take longer to be included in a block, and may even be dropped if the mempool becomes full. Bitcoin transactions may remain unconfirmed due to lower transaction fees for a number of reasons: 
   • When transaction fees are low, miners may be less likely to include those transactions in the blocks they mine.
   • Even if a transaction is included in a block, it may take additional blocks before it is considered fully confirmed. 
   • Some miners may choose to mine only blocks that include transactions with higher fees, meaning that lower-fee transactions could take longer to be confirmed.
2. Transaction is larger than the block size limit: Another reason for an unconfirmed transaction can be if the transaction is larger than the block size limit. Transactions that are larger than the block size limit are often not included in blocks by miners because they cannot be included in a block. The block size limit is the maximum amount of data that can be included in a block. Bitcoin transactions may remain unconfirmed if the transaction is larger than the block size limit because the network may be unable to process the transaction in a timely manner.
3. Congested with other transactions: One more reason for an unconfirmed transaction may be that the blockchain is congested with other transactions. When the blockchain is congested, miners will prioritize transactions with a higher fee attached to them.
4. Insufficient funds: Transactions need to be properly funded in order to be included in a block. If the transaction doesn’t have enough fees to cover the network fee, it will likely remain unconfirmed.
5. Older Protocols: Bitcoin transactions may remain unconfirmed due to older protocols for a number of reasons:
   • Older protocols may not support the new features that have been added to the Bitcoin network, such as Segregated Witness (SegWit). 
   • Older protocols may not be compatible with the new software that is required to run a full node.
   • Older protocols may not be able to correctly process the new transaction types that have been introduced, such as the Lightning Network.

2. Incomplete Transactions: These transactions are incomplete as something went wrong on the network and troubleshooting can be done to sort the issues with these transactions.

1. Incorrect Wallet Address: When sending a transaction, you need to include the receiver’s wallet address and the amount you want to send. If any of these details are incorrect, the transaction will be sent to the wrong address and will not be confirmed.
2. Internet failure: A faulty internet connection means that the transaction is not broadcasted to the bitcoin network. If the internet is working check to make sure that the firewall is not blocking the Bitcoin application.
3. Rejected transactions: Too many rejected transactions on the bitcoin network may lead to a congested network and eventually to a failed transaction.
4. Inactive user: Sometimes it may appear that the transaction is being confirmed by multiple nodes but still the transaction is unconfirmed as some wallets are not synchronized with the blockchain network. 

How to Reverse Unconfirmed Transactions?

There is no sure way to reverse a Bitcoin unconfirmed transaction. However, there are a few methods that may work, depending on the situation:

• If the transaction is stuck because it pays too low a fee, you can sometimes use a service like Replace-By-Fee (RBF) or Child Pays For Parent (CPFP) to increase the fee and get it confirmed.
• If the transaction is double-spent, you may be able to use a service like Replace-By-Fee to replace it with a higher-fee transaction.
• If none of the above methods works, you may have to wait for the transaction to eventually confirm, or simply cancel it and send a new transaction.

What to do if a Transaction is Unconfirmed for a Long Time?

Usually, a bitcoin transaction takes up to 48 hours to show the confirmation status. However, there are a few options to consider in case the bitcoin transaction is unconfirmed for too long:

1. Bitcoin transaction accelerator: The most popular way to cancel a bitcoin transaction is by using a Bitcoin transaction accelerator. These are special services that allow you to push your transaction through the Bitcoin network faster by paying a small fee. If the transaction is not too large and does not have too many inputs, you may be able to use a service like the Bitcoin Transaction Accelerator to get it confirmed faster.
2. Replace-By-Fee (RBF): If a bitcoin transaction is unconfirmed, it can be canceled by using a technique called Replace-by-Fee (RBF). RBF allows a new transaction to be created that replaces an unconfirmed transaction. The new transaction will have a higher fee than the unconfirmed transaction, and will therefore be more likely to be included in the next block. The previous transaction will be canceled and the associated funds will be refunded to your wallet.
   • The option for RBF is enabled in the wallet by clicking on a checkbox before accepting the transaction.
   • RBF allows the sender to speed up a transaction’s confirmation.
3. Child Pays For Parent (CPFP): In CPFP when the transaction with a low fee is not being confirmed fast enough for the recipient’s liking, the recipient will create a new transaction known as a child transaction spending the bitcoin received in the previous transaction known as parent transaction. The child transaction will pay a higher fee, signaling to the miners that they must mine the first transaction in order to mine the second transaction. The recipient will receive funds faster despite the fact that the sender paid the low fees at the time of broadcasting the parent transaction.
4. Double-Spent Method: If the transaction is not canceled, you can try again with a higher fee. Miners will pick up the new transaction due to higher fees and complete the operation. Bitcoin has measures to deal with double-spending in the network. This will effectively cancel out the first transaction as it will be considered invalid due to the double-spending. A second client or another wallet is required to initiate a new transaction with the same data but high transaction fees.  

How to Ensure Confirmation of Transaction?

The most common way to ensure confirmation of a bitcoin transaction is by including a transaction fee. This fee goes to the miner who confirms the transaction and includes it in the blockchain. The higher the fee, the more likely the transaction is to be included in the next block. The confirmation of the bitcoin transaction can be ensured by waiting for the transaction to be included in a block and then waiting for the block to be added to the blockchain. The bitcoin transaction can be confirmed by ensuring that all the required details are included in the transaction. This can be done by checking the bitcoin wallet for the required details.