How Bitcoin Transactions Work | Transaction Fees, Processing Times, and More

By Rebecca Campbell
Updated 24 May 2024

Transactions, often referred to as TX, play a crucial role in the functioning of cryptocurrencies like Bitcoin. They are the foundation of this digital payment system, enabling us to swiftly, securely, and effortlessly access and utilize our funds. Therefore, comprehending the concept and mechanics behind transactions is vital for gaining insights into the inner workings of cryptocurrencies. Additionally, this knowledge will enhance your understanding of the endless opportunities this system presents daily.

Key Takeaways

  • When you make a Bitcoin transaction, you move Bitcoin from one address to another. To ensure the transaction’s validity, the sender must sign it.
  • Unlike traditional accounts, Bitcoin operates differently. Instead, Bitcoin is divided into pieces of various sizes, all associated with a specific address. These addresses are controlled by the owners of the Bitcoin and are referred to as Unspent Transaction Outputs (UTXOs).
  • Every Bitcoin transaction is recorded in the mempool, initially marked as ‘pending.’ Once a miner includes the transaction in a block, it becomes confirmed.
  • The Bitcoin blockchain serves as a colossal, shared, and encrypted record of all addresses that hold Bitcoin balances.
  • Blockchains are a sequence of individual blocks arranged chronologically based on the order of transactions.

What is a Bitcoin Transaction?

At its core, a transaction represents the movement or exchange of value between two parties. Within the Bitcoin network, these transactions symbolize the transfer of bitcoins among individuals connected to the network. However, these transactions are data entries stored within the Bitcoin blockchain. In simpler terms, they are streams of information.

Therefore, Bitcoin transactions can be perceived as direct messages containing programmable details, digitally signed through cryptography, and disseminated across the entire network for validation. Moreover, due to the transparent nature of the Bitcoin network, these transactions are easily traceable within its blockchain, allowing for the verification of every single transaction since the inception of Bitcoin.

The Elements That Make up a Bitcoin Transaction

You may be curious about the components of a Bitcoin transaction. Let’s delve into these elements quickly;

  • Inputs: Inputs serve as references to previously unused outputs from past transactions. They play a crucial role in verifying the origin of assets involved in a transaction and contain the address where the bitcoins were initially received.
  • Outputs: Outputs encompass the destination address and the amount being transferred. Additionally, they include change or return addresses, enabling transactions to comprise multiple outputs.
  • Identifier (TXid): Every transaction has a unique hash derived from inputs and outputs. This hash serves as an exclusive and non-reproducible identifier within the blockchain.
  • Commission Rate: The commission, or fee, represents a nominal payment miners receive for processing transactions. When miners generate a new block, they receive fees for each transaction incorporated. The commission does not explicitly appear within the transaction content or associate with any specific output since the recipient miner remains unknown. Instead, a designated amount is left unassigned to any output, signifying it as a commission for miners.

How are Bitcoin Transactions Processed?

When it comes to sending or exchanging bitcoins, several underlying processes are involved to ensure a smooth transfer of the digital currency. Both the Bitcoin wallet and the network play crucial roles in facilitating this. Here are two fundamental terms associated with these processes:

  • Public key: Also referred to as a Bitcoin address, the public key is similar to a username on social media platforms. It is publicly known and needs to be shared with the sender to receive bitcoins.
  • Private key: Unlike the public key, the private key must be kept confidential, similar to the password for your social media accounts. Private keys are of utmost importance in the realm of cryptocurrencies. They grant access to bitcoins; if forgotten, there is no way to recover the bitcoins or the private key. We strongly recommend that you create a secure backup of the private key.

Unless you are a blockchain “miner,” there is limited scope for you to verify a transaction independently. Instead, you rely on the expertise of professionals. You are assigned a unique “private key” to make the request whenever you initiate a Bitcoin transaction. Only you can access this key, which is automatically generated for each transaction.

You use the private key to broadcast the transaction request across the Bitcoin network. Miners and others receive your request and privately engage in mining activities to solve the coded request. While the mining process is intricate and beyond our current scope, it plays a crucial role in verifying Bitcoin transactions.

Once a miner successfully solves the request, they add it to their version of the blockchain ledger. Subsequently, other miners and network participants, known as nodes, validate the correctness and validity of the first miner’s proposal. The new block containing all these transactions is added to the public blockchain upon consensus. By becoming part of a block in the blockchain, your transaction is confirmed.

Each block in the blockchain is mathematically linked to the preceding block. After your transaction block joins the chain, the subsequent blocks serve as additional confirmations of its legitimacy. Therefore, each following block acts as further confirmation, bolstering the legitimacy of your transaction.

Can Bitcoin Transactions be Traced?

Tracing a Bitcoin (BTC) transaction is indeed feasible. Bitcoin explorers provide a means to visualize the activity on the blockchain. This transparency enables tracing transactions, likening the blockchain to an accessible database replete with Bitcoin transaction records. Other cryptocurrencies, such as Ether (ETH) and Solana (SOL), also possess their respective blockchain explorers known as Etherscan and SolScan.

Within these explorers, one can discover transaction details on the blockchain, including the amount of crypto transferred and the involved addresses. Despite the blockchain’s transparency, some believe it is still possible to conduct Bitcoin transactions anonymously. However, many countries are adopting Know Your Customer (KYC) regulations, mandating identity disclosure on centralized trading platforms.

By revealing one’s identity, it becomes substantially easier for authorities to uncover transaction history and assess the contents of a Bitcoin wallet. When engaging in trading activities on a centralized exchange, personal information must be provided to the platform. Consequently, Bitcoin addresses can be linked to personal data. Given that the data from past Bitcoin transactions remains preserved, it remains perpetually feasible to review prior transactions.

How Long Do Bitcoin Transactions Take?

A Bitcoin transaction typically undergoes multiple verifications on the blockchain before being fully validated. This precautionary measure aims to mitigate the risks associated with unconfirmed transactions, such as potential reversals or double cryptocurrency spending. Each confirmation occurs when a new block is added to the blockchain. Some entities may require up to six confirmations for substantial cryptocurrency transfers to businesses.

On the Bitcoin network, the average time for a BTC payment to receive a confirmation is approximately 10 minutes. However, transaction durations can vary significantly. Various factors influence these timings, including overall network activity, hash rate, and transaction fees. During periods of high network congestion, a backlog of transactions accumulates in the mempool. As a result, users may need to pay higher transaction fees to expedite their transactions and ensure prompt processing.

Different Factors That Influence Bitcoin Transactions

Network Activity

When it comes to Bitcoin transactions, they enter a sizable queue known as a mempool, which acts as a storage space. Within the mempool, transactions await their turn to be processed by miners. Occasionally, a surge of transactions floods the mempool simultaneously, causing some transfers to face longer waiting periods before being included in the next block. At times, transfers with low fees might even be rejected by the mempool. It’s worth noting that Bitcoin has a maximum capacity of processing up to seven transactions per second.

Spam Attacks

Bitcoin has long been a target for hackers, with spam and dusting attacks being additional factors impacting network transactions. During a spam attack, malevolent actors relentlessly attempt to overload the mempool with a high volume of transactions. To make matters worse, these hackers exploit transactions with low fees, putting strain on the network’s resources.

Hash Rate

More miners can also contribute to delays in transaction confirmations. Miners require adequate incentives to continue mining new blocks diligently. If the rewards for their efforts diminish, the hash rate, which signifies the computing power dedicated to mining, may drop abruptly. This reduction in hash rate implies a scarcity of miners available to mine new blocks and confirm each transaction swiftly.

What is a Bitcoin Mempool?

A mempool serves as a repository for all pending Bitcoin transactions that await validation and inclusion in the subsequent block of the blockchain. Each node within the network temporarily maintains its own copy of the mempool. When a new block gets appended to the blockchain regularly, the mempool undergoes a clearing process. However, they must meet a minimum fee requirement to process and confirm transactions. Transactions with lower fees typically endure a waiting period within the mempool that spans beyond a single block before they are ultimately processed and confirmed.

Bitcoin Transaction Fees

The fees associated with sending Bitcoin can vary greatly, ranging from a few cents to as much as $100. This wide range is attributable to the interplay of supply and demand within the Bitcoin network, which is influenced by congestion levels at any given time and the complexity of your specific transaction. The number of inputs involved primarily determines transaction complexity. If your transaction incorporates numerous inputs, it will occupy more block space, necessitating a higher fee. Each block within the blockchain can only accommodate up to 1MB of data.

Consequently, a finite capacity exists for transactions in each block. Miners, responsible for ordering transactions into blocks, receive rewards through a block subsidy (newly created bitcoins) and transaction fees. As a result, they are motivated to prioritize transactions with higher fees. Bitcoin users can influence the transaction processing speed by adjusting the fee rate. Opting for a higher fee rate ensures a faster processing time for the transaction.

How Many Confirmations Does a Bitcoin Transaction Need?

The required number of confirmations for a cryptocurrency transaction to be processed varies depending on the exchange and, in some instances, the transfer amount. Certain exchanges proceed with transactions after a single confirmation, while others mandate three confirmations. There are even instances where up to six confirmations are necessary. It is worth noting that several Bitcoin wallets only process transactions once they have received a minimum of three confirmations.

Different Types of Bitcoin Transactions

Here are various formats used for Bitcoin transactions:

Segregated Witness (SegWit) with Bech32

Bitcoin implemented the SegWit protocol in 2017, enabling faster validation and other improvements. Transactions using SegWit are formatted as Bech32, and wallets supporting SegWit often offer lower fees. “Bech32” comes from BCH encoding and consists of 32 characters.

Pay to Public Key (P2PK)

This is the original type of Bitcoin transaction, where funds are sent to a public key. The following transaction types hashed the public key to protect against future quantum computers decrypting the private key.

Pay to Public Key Hash (P2PKH)

P2PKH is the standard format for transactions that pay to a hashed Bitcoin address. The SegWit version is known as P2WPKH.

Pay to Script Hash (P2SH)

P2SH supports advanced features like multi-signature requirements for payment authorization. The SegWit version is called P2WSH.

Pay to SegWit Public Key Hash (P2SH (P2WPKH))

This format combines native SegWit with a P2SH transaction.

Pay to Taproot (P2TR)

Bitcoin adopted the Taproot protocol in late 2021, offering enhanced privacy and transaction efficiency.

Internal Vs. External Bitcoin Transactions

An internal transaction refers to a trade that occurs within the inner workings of a business without involving any external third parties. It operates within the organization’s internal functions and doesn’t involve the exchange of resources. Internal transactions are limited to interdepartmental interactions and do not directly affect cash flow.

An external transaction, on the other hand, involves interactions with external third parties. It serves as a medium of exchange between internal and external organizations. As these transactions involve exchanges with third parties, they significantly impact the business’s cash flow.

The Advantages of Bitcoin Transactions

Here are some of the benefits of Bitcoin transactions:


Unlike traditional financial systems that require hours or even days for transaction approval, Bitcoin offers a faster, easier, and more cost-effective process. It eliminates the need for intermediaries to validate and approve transactions. Instead, Bitcoin relies on a network of interconnected nodes to verify transaction information, making the process quicker, safer, and more reliable.

Immutable Transactions

Once a Bitcoin transaction is added to the blockchain, it becomes virtually irreversible and resistant to modification. This feature provides a significant advantage in various economic and financial domains, as it eliminates the possibility of cancellations or refunds after the transaction is completed.

Enhanced Security

Bitcoin transactions utilize public addresses and private keys. Private keys are a form of authorization to spend bitcoins, similar to a PIN or password. Public addresses enable the secure sending and receiving of Bitcoin transactions, minimizing the risk of theft or unauthorized access.

Lower Transaction Fees

Compared to traditional systems and banks that often charge high percentages as transaction fees, Bitcoin offers lower commissions. Regardless of the amount, cryptocurrency transactions can cost just a few cents. This is because fees are based on the transaction size rather than the transaction value, resulting in more cost-effective transactions.

Final Thoughts on How Bitcoin Transactions Work

Bitcoin is not tangible like a physical coin, token, or paper note. Instead, it is a digital asset represented by a series of verified transactions recorded on the blockchain. Transactions form the foundation of the Bitcoin system, playing a vital role in its operation. Every aspect of Bitcoin is carefully designed to enable the creation, transmission, validation, and ultimate inclusion of transactions in the universal ledger.

Frequently Asked Questions

How are Transactions Added to Bitcoin?
In the case of a public blockchain like Bitcoin, the process of adding a transaction to the chain relies on consensus. This means that most nodes, which are computers in the network, must agree that the transaction is valid. Those who operate these computers are motivated to verify transactions through rewards.
How are Bitcoin Transactions Verified?
To ensure the legitimacy of a Bitcoin transaction or any other cryptocurrency transaction, it must undergo verification on the blockchain. When a transaction is confirmed, it means that it has been included in a block, which in turn, is added to the blockchain.
What Information is Stored in a Bitcoin Transaction?
A Bitcoin block contains three key components. It stores transaction details such as the transaction date, time, and amount. It also includes participants' information, which is identified by their unique digital signatures. Additionally, each block has information that distinguishes it from others in the blockchain.
Can a Bitcoin Transaction be Reversed?
Simply put, once a cryptographic transaction has been completed, it cannot be reversed or altered.
What Ensures the Security of Bitcoin Transactions?
The security of your Bitcoin ownership relies on the blockchain, where your ownership records are securely stored, validated, and encrypted. Cryptocurrency encryption methods have thus far prevented any successful theft or manipulation of blockchain information.
How Bitcoin Transactions Work

How Bitcoin Transactions Work

By Rebecca Campbell - min read
Updated 24 May 2024
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