A Bitcoin transaction must be verified by the Bitcoin network before it can be completed. This verification is performed by so-called Bitcoin miners, which are really just powerful computers that all run Bitcoin’s code and store its blockchain. When someone sends a Bitcoin to someone else, the transaction is transmitted 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 remains on the network as an unconfirmed transaction. Most Bitcoin wallets won’t allow you to spend unconfirmed transactions, so you’ll have 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. Transaction processing: These transactions are incomplete but are processed on the network. There are several reasons for the pending status of processing transactions on the bitcoin network:
- Low-cost transaction: The most common reason for an unconfirmed transaction is that it is a low-cost transaction. Low-cost 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 transmitted to the network immediately. As a result, these transactions can remain unconfirmed for a long time. Bitcoin transactions can remain unconfirmed due to lower transaction fees because miners can prioritize other transactions that have higher fees. This means that the transaction with the lowest fee can take longer to be included in a block and can also be abandoned if the mempool becomes full. Bitcoin transactions can 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 it mines.
- Even if a transaction is included in a block, additional blocks may be required before it is considered fully confirmed.
- Some miners may choose to mine only blocks that include transactions with higher fees, which means that transactions with lower fees may take longer to be confirmed.
- : Another reason for an unconfirmed transaction may be if the transaction is greater than the block size limit. Transactions 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 can remain unconfirmed if the transaction is above the block size limit because the network may not be able to process the transaction in a timely manner.
- : One more reason for an unconfirmed transaction could be that the blockchain is congested with other transactions. When blockchain is congested, miners will prioritize transactions with a higher fee.
- Insufficient funds: Transactions must be properly funded to be included in a block. If the transaction doesn’t have enough fees to cover the network fee, it will likely remain unconfirmed.
- Older protocols: Bitcoin transactions may remain unconfirmed due to older protocols for a number of reasons:
- Older protocols may not support new features that have been added to the Bitcoin network, such as Segregated Witness (SegWit).
- Older protocols may not be compatible with new software required to run a full node.
- Older protocols may not be able to properly process new transaction types that have been introduced, such as the Lightning network.
The transaction is greater than the block size limit
Congestion with other transactions
2. Incomplete transactions: These transactions are incomplete since something has gone wrong on the network and troubleshooting can be done to resolve issues with these transactions.
Incorrect wallet address
- : When sending a transaction, you must include the recipient’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.
- Internet error: A faulty internet connection means that the transaction is not transmitted to the bitcoin network. If the Internet is working, check that the firewall is not blocking the Bitcoin application.
- Declined transactions: Too many declined transactions on the bitcoin network can lead to a congested network and eventually a failed transaction.
- Inactive user: Sometimes it may appear that the transaction is confirmed by multiple nodes, but the transaction is still not confirmed since some wallets are not synchronized with the blockchain network.
How to reverse unconfirmed transactions?
There is no secure way to reverse an unconfirmed Bitcoin transaction. However, there are some methods that can work, depending on the situation:
- If the transaction is blocked 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 spent twice, 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 work, you may need to wait for the transaction to be confirmed or simply cancel it and submit a new transaction.
How to cancel a Bitcoin transaction if it is not confirmed?
Usually, a bitcoin transaction takes up to 48 hours to show the confirmation status. However, there are some options to consider in case the bitcoin transaction is not confirmed for too long:
- Bitcoin transaction accelerator: The most popular way to cancel a bitcoin transaction is to use 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 isn’t too big and doesn’t have too many inputs, you may be able to use a service like Bitcoin Transaction Accelerator to confirm it faster.
- Replace-By-Fee (RBF): If a bitcoin transaction is not confirmed, it can be canceled using a technique called Replace-by-Fee (RBF). RBF creates a new transaction that replaces an unconfirmed transaction. The new transaction will have a higher fee than the unconfirmed transaction and therefore will 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 a check box before accepting the transaction.
- RBF allows the sender to speed up the confirmation of a transaction.
- Child Pays For Parent (CPFP): In CPFP when the transaction with a low fee is not confirmed fast enough for recipient credits, the recipient will create a new transaction known as a child transaction that spends the bitcoin received in the previous transaction known as the parent transaction. The child transaction will pay a higher fee, signaling to miners that they need to mine the first transaction 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 transmission of the main transaction.
- Double opt-out method: If the transaction is not canceled, you can try again with a higher fee. Miners will collect 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 the first transaction as it will be considered invalid due to double spending. A second client or wallet is needed to initiate a new transaction with the same data but high transaction fees.
How to guarantee confirmation of the transaction?
The most common way to ensure confirmation of a bitcoin transaction is to include 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 it is that the transaction will be included in the next block. 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 making sure that all required details are included in the transaction. This can be done by checking the bitcoin wallet for the required details.