What happens when you send an Ethereum transaction

02 September 2026

You click "Send" on your wallet. Behind the scenes, a precise sequence of events begins. Understanding this process helps you see why fees vary, why confirmations matter, and what "final" really means.

Step one: Construction and signing

Your wallet builds a transaction object. It includes the recipient address, the amount of ETH (or a token), a nonce (a counter that prevents double-spending), the gas limit, and the maximum fee you're willing to pay per unit of gas. Since the London hard fork and EIP-1559, every transaction also specifies a "max priority fee" - an optional tip to validators - and a "max base fee" that caps your total.

Your wallet signs this object with your private key. The signature proves only you could have authorized the transaction. No signature, no validity.

Step two: Broadcasting and the mempool

The signed transaction goes to the network. Your wallet sends it to one or more Ethereum nodes. Those nodes rebroadcast it to their peers. Within seconds, the transaction reaches thousands of nodes.

Nodes run a sanity check: is the signature valid? Does the sender have enough ETH? Is the nonce correct? If a transaction fails these checks, nodes drop it. If it passes, it joins the node's mempool - the waiting room for unconfirmed transactions.

Here is where EIP-1559 matters most. The base fee adjusts automatically based on network congestion. When the network is busy, the base fee rises. When it's quiet, it falls. Your transaction's fee must at least match the current base fee. The priority fee you add determines your place in line among transactions at the same base fee level. A higher tip means validators are more likely to include your transaction in the next block.

Step three: Block proposal and inclusion

Ethereum runs on a proof-of-stake consensus. Every 12 seconds, one validator is pseudo-randomly chosen to propose a block. That validator picks transactions from its mempool, typically those with the highest priority fees. It orders them, executes them against the current state, and builds a block.

Once the proposer broadcasts its block, the clock starts. Other validators must attest - vote - that the block is valid. They check that the proposer didn't cheat, that all transactions execute correctly, and that the block's hash is consistent. Validators who attest honestly earn rewards. Those who attest dishonestly get slashed - their staked ETH destroyed.

Your transaction is now included in a block. This is the first confirmation. You can see it on a block explorer. But inclusion is not final.

Step four: Finality

Ethereum finalizes transactions after two epochs. One epoch is 32 slots, or 6.4 minutes. So finality arrives roughly 12.8 minutes after inclusion, assuming no hiccups.

Finality means an economic guarantee. Once a block is finalized, reverting it would require burning at least one-third of all staked ETH - roughly 11 million ETH at current staking levels. That cost is astronomically high. The network will not reorganize or undo finalized blocks except in a catastrophic failure.

This is the key distinction: inclusion means your transaction appears in a block. Finality means the network promises it will never be undone. For most everyday transfers, inclusion is enough - exchanges and services accept one confirmation for small amounts. For large sums, waiting for finality is prudent.

How fees shape your experience

Under EIP-1559, the base fee is burned, not paid to validators. Only the priority fee goes to the proposer. This mechanism makes fee estimation straightforward: if you set your max base fee higher than the current base fee, and include a modest priority fee, your transaction usually gets included within a few slots. If the base fee spikes while your transaction is in the mempool, your transaction might sit until base fees drop below your max.

You can always replace a pending transaction by sending a new one with the same nonce and a higher fee. This is called a "speed-up" and is handled by most wallets.

Practical takeaways

• Your transaction isn't "done" when it appears on Etherscan. It's included. Finality takes roughly 13 more minutes.
• Priority fee determines inclusion speed more than base fee, because base fee is uniform for all transactions at a given moment.
• If you accidentally set a very low gas price, your transaction can linger in the mempool for hours - or days - until the base fee falls enough.
• The system favors patience: you can always cancel or replace a stuck transaction by sending a new one with the same nonce and zero value.

That's the journey. From your wallet to the mempool, from proposal to attestation, from inclusion to finality. Each step is designed so that one person's click becomes an irreversible part of Ethereum's state - but only after the economic guarantees lock in.

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