How to change or cancel a pending Ethereum transaction

Ethereum is an open source blockchain-based software platform with thousands of decentralized applications (DApps) that power their native cryptocurrency Ether (ETH), which can be sent and received worldwide.

Ethereum was first conceived in 2013 by the Russian-Canadian programmer Vitalik Buterin and is designed as a platform for self-executing, permanent and immutable DApps with different use cases, from finance to games to art.

DApps, commonly known as Smart Contracts, are ETH transaction protocols that automatically perform certain functions and actions like processing transactions with predefined terms and agreements. Submitting a transaction, canceling it, or processing an outstanding Ethereum transaction are actions related to the operation of smart contracts.

What is an Ethereum transaction?

Transactions are cryptographically signed instructions from accounts.

The ETH network supports two main types of transactions: contract delivery transactions that have no recipients and regular transactions, the simplest type of transaction used to transfer ETH from one wallet to another.

A regular, sent ETH transaction contains the identifier of the sender or a signature that is generated when the private key of the sender signs the transaction and confirms that the sender has authorized the particular Ethereum transaction. The receiving address, the amount of ETH to be transferred from the sender to the receiver, information on ETH transaction fees and an optional field containing any data are all part of a regular Ethereum transaction that is sent.

 ETH transactions must be mined to be valid and require a fee from the sender.

Ethereum miners verify legitimate transactions to get rewards for their work in generating new ETH. When a miner solves a cryptographic (mathematical) puzzle, a transaction is considered validated. ETH , like Bitcoin (BTC), has a Proof-of-Work (PoW) system to prevent cyberattacks from an individual or group.

Requiring users to pay transaction fees when using the blockchain protects the Ethereum network from sloppy or malicious computing tasks, such as:

Ethereum transaction lifecycle

An ETH transaction goes through a series of states, starting with an indefinite state, until it is confirmed in a block.

Unknown: Unknown status refers to a transaction that was not seen or processed by the network.

Unsolved: When a transaction is in a pending state, it waits for miners to accept and process it in what is known as a pooled transaction, also known as a “mempool”. Since miners prioritize higher gas prices, transactions with lower gas values ​​in the pending phase can be delayed for a long time. Lowest gas price transactions may never be picked up, leaving you “stuck” in a pending state forever.

In blocks: If a miner successfully selects a transaction and mines in a block, it changes to the state in the block. The transactions in the block are called mining transactions. When the block is bifurcated, a transaction within the block can return to a pending state. When a broken transaction (i.e., a block state transaction) is rolled back from the network, it is known as a forked transaction.

Replaces: A transaction can be moved from the pending state to the replaced state if any of the following occurs:

• A new transaction with the same nonce from the same sender goes into the block status, or
• Another transaction with the same month and 12% higher gas prices entered the pending phase, this time from the same sender.

Confirmation of the Ethereum transaction

 ETH s transaction confirmation is the number of blocks generated since the first block containing this transaction.

A pending ETH transaction must receive a certain number of confirmations. The higher the gas fee, the greater the certainty that the Ethereum network has processed and confirmed the transaction.

Recently used blocks can be reorganized, giving the impression that transaction processing has failed. Nevertheless, the transaction can be included in another block and still be valid. The probability of a reorganization decreases with each further cleared block, ie the more confirmations, the more unchangeable the transaction becomes.

Confirmation of the Ethereum transaction

A transaction fee is an incentive that users pay to block miners. It is used to send a specific transaction on the ETH blockchain.

Transaction fees on the ETH blockchain are also known as gas fees because they refer to gas, a pricing mechanism used on the Ethereum network that relates to the computation required to process a miner’s transaction. The computing tasks of a transaction are measured against the gas costs.

On the other hand, every gas unit has a gas price in ETH. While the complexity of a particular transaction determines the cost of gas, users can set their own gas prices and limits, or the maximum number of units of gas that the transaction will consume.

What is a nonce?

Nonce is an acronym for “number used only once” and refers to the total number of confirmed transactions sent from a given Ethereum address.

Ethereum wallets can transfer multiple transactions from one account with little latency between other accounts, which means that the nonce calculation is seen as the necessary mechanism to determine which transactions are processed first. Usually, Ethereum wallet applications take care of nonce management for users.

How do I cancel an Ethereum transaction?

There are two main methods to void pending Ethereum transactions: in-app void and custom nonce.

Typically, Ethereum transactions are pending or stuck for hours when users send with low gas prices. As a result, users often find it necessary to change Ethereum transactions.

It should be noted that an attempt to cancel can only be made if the transaction is still pending in the network. As a first step you have to check in the block explorer whether the transaction is still pending. Mainly for inserting the transaction hash, also known as the Ethereum transaction ID, and if the block explorer says “pending” the user can still try to cancel it.

The easiest way to cancel a stalled Ethereum transaction is to cancel in the app, exit the user from the Ethereum wallet app and close their browser, reopen it and log back into the app.

If these steps don’t solve the problem, the second route to salvation comes.

Canceling a pending Ethereum transaction by setting a custom nonce means that a 0 ETH transaction with a high gas price will be created to the user’s own address to prevent the previous transaction from getting stuck. Before submitting this second transaction, users should write down the nonce used by the original pending transaction, and then reuse the recorded nonce.

If a user has a lot of pending Ethereum transactions, it is best to start with the oldest transaction or lowest nonce value.

How can you speed up Ethereum transactions?

Users can speed up a slow Ethereum transaction by adding gas. This move could encourage Ethereum miners to prioritize it.

If an Ethereum user undercuts the price of gas, other users have the option to bid a higher bid than this original bid and the transaction will remain pending. If a transaction gets stuck, the network will not confirm any new transactions from the same wallet address until the miner confirms the first transaction.

In this situation, the user can either wait for the carrier to be ready to process the transaction at the set price or resend the original transaction but with a higher gas charge. By clicking the “Expedite” button in your Ethreum wallet, the transaction can be processed faster.

If the previous step didn’t work, the user can go to the Advanced tab to set the gas price manually.

Finally, users should look up the transaction in the blockchain explorer by posting their hash to see if it was processed successfully. If the transaction does not appear immediately, you will have to wait a few minutes and refresh the page.

Can Ethereum transactions be reversed?

Ethereum wallets cannot undo completed Ethereum transactions.

If an Ethereum user accidentally sends money to the wrong address or sends the wrong amount to ETH, they can cancel the transaction while it is pending. Once the transaction has been confirmed and shown as “Successful”, which means that it has been added to the next block, it cannot be undone. The Ethereum blockchain is immutable, so the data entered into the blocks is immutable. With that in mind, it is important to ensure that the transaction details are correct before hitting the submit button.

Finally, it’s worth noting that many blockchain startups have developed mechanisms that allow users to reverse Ethereum transactions.