Ethereum is preparing to retire a long-standing assumption around ETH transaction fees as its next major upgrade introduces different costs for existing and newly created addresses.

Under the upcoming Glamsterdam upgrade, sending ETH to an address that already exists will still require 21,000 gas. However, transfers to an address that has never been recorded on Ethereum will cost more because the network must create and permanently store a new account.

The Ethereum Foundation has warned wallet providers, blockchain trackers and fee-estimation tools to update systems that treat 21,000 gas as a fixed cost for every basic ETH transfer. Gas represents the computational work required to process activity on Ethereum, with users paying network fees in ETH.

The proposed change adds 183,600 units under a new category known as state gas for transactions involving previously unused addresses.

Ethereum’s 21,000-Gas Assumption Faces a Major Change

The 21,000-gas figure has been deeply embedded in Ethereum software. Wallets commonly use it to determine the amount of gas needed for basic ETH payments, while other blockchain services use the figure when processing transactions.

That assumption could create issues once Glamsterdam goes live. Software that considers 21,000 gas to be the maximum cost of a standard ETH transfer could underestimate fees or incorrectly reject valid transactions.

The distinction comes down to the amount of work Ethereum must perform. Sending funds to an existing account only requires updating balances that are already part of the network’s state. Sending ETH to a completely new address requires Ethereum to create an account record and maintain it permanently.

Although the two operations require different resources, Ethereum has historically charged the same amount for both.

Glamsterdam Will Be Tested Before Mainnet

Developers still have an opportunity to identify compatibility issues before the upgrade reaches Ethereum’s main network.

Glamsterdam will first activate on Platåberget, a test environment that uses tokens without real monetary value. Developers can use the network to test the new rules and address potential problems.

The upgrade is then expected to move to the Sepolia and Hoodi testnets before eventually reaching Ethereum’s mainnet.

For ordinary ETH holders and users, no immediate action is required. The change primarily affects wallet providers, blockchain infrastructure, fee calculators and other applications that rely on the traditional 21,000-gas assumption.