Bitcoin Transaction Stuck? Here’s Why and What You Can Do

Beginner’s Guide / 16.05.2020

As Bitcoin gains increased mainstream adoption currently being used as a means of payment, the number of transactions on the Bitcoin network has increased significantly over the past few years. And with the recent 2020 Bitcoin halving event, the Bitcoin network is expected to handle even more transactions as more blocks continue filling up. However, with increased transactions, not all of them are verified and added straight away in the blockchain. Sometimes, due to several reasons, Bitcoin transactions fail to confirm or become “stuck”.

One reason that could explain why transactions get stuck is that miners “prefer” transactions with transaction fees and include them in their blocks almost immediately. Transactions with lower fees, normally referred to as “outbid transactions” and remain in miners’ mempools for quite long until a new block is mined. Correspondingly, if the transaction becomes outbid for a second time, it will have to wait longer (even days) maybe until the next block to be confirmed.

While these transactions are finally confirmed after several days, not every trader has the patience to wait that long or put up with the inconvenience that comes with stuck transactions. Nonetheless, there are tools and mechanisms you can use to prevent or clear stuck Bitcoin transactions. Here is a guide on solving Bitcoin transactions stuck.

Why Do Bitcoin Transactions Get Stuck?

While there could be plenty of reasons for a transaction to become stuck, including Bitcoin’s scalability problem, low transaction fee is the most commonly known reason. Bitcoin transaction fees are calculated using fee density where fee density (d) is obtained by dividing the transaction fee (f) in satoshis by its size(s) in bytes. So, the transaction fee is: d=f/s.

Initially, as Bitcoin was starting before the fame, Bitcoin transaction fees held an insignificant portion of miner revenue. In fact, outgoing transaction fees were pegged at 0.1mBTC. Miners held a significant space in their block; hence transactions were confirmed quite fast regardless of how low the transaction fee was. However, things have since changed. Today Bitcoin blockchain handles over 200, 000 transactions a day compared to close to 1, 000 transactions a day in 2012.

Massive increase in transactions on the Bitcoin network has resulted in increased demand for block space leading to increased competition among miners for block space. Transactions cost can no longer be fixed at 0.1mBTC as it would be insufficient to have a transaction included in the next block. Bitcoin transactions before being confirmed are held up in a backlog pool known as mempool.

Miners then collect the transactions from the mempool usually in the priority of the amount of transaction fees attached. Transaction with higher fees outbids low fee transactions which would probably be confirmed after a while.

How to Prevent Your Bitcoin Transaction from Getting Stuck

There are several mechanisms to prevent stuck Bitcoin transactions. Alternatively, you can use Bitcoin transaction accelerators to quicken transaction confirmation even when a low transaction fee is attached. Here are some effective mechanisms to stop Bitcoin transactions from getting stuck. They are categorized as pre-transaction, post-transaction and also at the receiver’s end.

Pre-transaction Mechanisms

  • Increase Transaction fees – As earlier mentioned, transactions with higher fees attached are confirmed pretty first. Therefore, you would want to increase the transaction fee to a reasonable price for quick confirmation. Depending on the type of Bitcoin wallet you’re using, you can increase the transaction fees manually to default on the wallet settings or input a fee each time you’re sending a transaction. There are websites such as 21.co  that can help you come up with a reasonable transaction fee per byte by monitoring the Bitcoin network. These websites also indicate how long you should expect the transaction to be verified.
  • Check whether your wallet has dynamic fees – Recently launched Bitcoin wallets support dynamic fees which allows transactions to be confirmed quite fast. Dynamic fees are basically additional transaction charges that make a transaction to be rapidly included in the next block hence preventing transaction stuck.

Post-transaction mechanisms

If you’ve already conducted a transaction then realize it’s stuck, there are two effective ways you can use to clear a stuck transaction or commonly referred to as “jump the queue.”: Opt-in Replace-by-fee and Child Pays for Parents.

  • Opt-in Replace-by-Fee (Opt-In RBF)-Opt-In RBF is the easiest way to make your transaction jump the queue by giving you a second chance to re-send the same transaction but with an increased fee. In normal terms, a re-sent transaction on the Bitcoin network is rejected by the nodes outright as they consider it a double spend. However, when you use Opt-In RBF, resent transactions with a higher are accepted as the network doesn’t regard them as double spend. While Opt-In RBF transactions have a higher chance of jumping the transaction queue in mempool, not all miners accept Opt-In RBF. But a large majority do accept. Two notable Bitcoin wallets that support Opt-In RBF as an option include Electrum and GreenAddress.
  • Child Pays for Parent (CPFP)- CPFP provides an alternative to Opt-In RBF in wallets that doesn’t support the latter. In CPFP, miners pick-up transactions with the most combined fees and not necessarily those with a high transaction charge. Bitcoin being an electronic cash system, transactions are basically a transfer of ownership of digital tokens as either “coins” or “tokens”. The transfer of value remains incomplete when a transaction gets stuck. In CPFP, a recipient can clear the transaction by spending one of its outputs with a transaction that pays not only for itself (the child), but also the original parent. A receiver can solve stuck transactions using CPFP as well.

Bitcoin Transaction Accelerators

Since not all miners accept Opt-In RBF and CPFP, these options may sometimes be ineffective. Bitcoin transaction accelerators are quite effective in fast-tracking transactions even when low fees are attached.

These platforms are an off-chain paid/ free request related to a mining pool to purposely include transactions in the next block regardless of the transaction fee attached. An offline fee market for the mining pools is consequently created.

Examples of best Bitcoin transaction accelerators include: ViaBTC, BTC.Com, and BitAccelerate among others. It would be best if you were careful when choosing Bitcoin accelerators as others, such as ConfirmTX are scam platforms.

The Bottom Line

With the number of transactions on the Bitcoin network has increased in recent years plus blocks increasingly filling up, not all transactions can be verified and included in the blockchain straight up. Waiting transactions are tucked in a sort of queue called mempools. Transactions with most fees are preferred by miners and are usually added to the block rapidly. Others, especially those with low transaction fees, become stuck.

To avert the inconvenience that comes with stuck transactions, you can either use Bitcoin transaction accelerators or several pre and post transaction mechanisms discussed above. Given the intense, volatile nature of bitcoin, transaction confirmation time could be the difference between a profit and loss.

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Wayne is a Blockchain enthusiast and expert in crypto trading. Currently, he covers trendy issues on digital currencies.