An Ethereum access list starts running up a gas bill before the listed accounts or storage fields are used. Under EIP-2930, one address with two storage keys costs 6,200 gas to include. That charge buys cheaper access during execution; it does not mean the whole transaction costs 6,200 gas or will necessarily be cheaper.
| What you need to know |
|---|
| EIP-2930 charges 2,400 gas per listed address and 1,900 per storage key. |
| These charges apply at the beginning of execution, alongside the transaction's other starting costs. |
| Duplicate entries are permitted but are charged more than once. |
| Execution can access addresses and storage keys outside the list, at the applicable higher access cost. |
The official EIP-2930 specification defines the list as addresses paired with storage keys. It adds those entries to sets that record which accounts and storage locations have already been accessed. In this gas-accounting system, a listed location is prepared in advance, rather than waiting for its first use during execution.
What the 6,200-gas example includes
The arithmetic is 2,400 for the address plus twice 1,900 for its two storage keys. Those are inclusion charges. The specification charges them at the start, without making payment conditional on a later read of every entry. An unused entry therefore still adds its listed cost. Base transaction costs, transaction data and the operations actually executed sit outside this small calculation.
Adding the same address again with an empty storage-key list adds another 2,400 gas. The example’s inclusion bill then becomes 8,600 gas, while the set of distinct prepared locations stays unchanged. EIP-2930 explicitly permits duplicates and says repeated inclusion makes no other difference to execution flow or outcome. A longer list can thus cost more without preparing anything new.
Compare preparation with the access it replaces
The companion EIP-2929 storage-read rules distinguish a first, or cold, read from an already prepared, or warm, read. They specify 2,100 gas for a cold storage read and 100 for a warm one. Combining the 1,900-gas list charge for a storage key with one 100-gas read gives 2,000 gas for those two components.
That 100-gas difference from a cold read is not the saving for an entire transaction: an address entry has its own charge, and other execution costs remain. Assessing a list requires comparing the complete execution with and without it. Counting listed keys alone would overlook both the address overhead and any entries that execution never uses.
The list also leaves room for unexpected accesses. EIP-2930 expressly allows execution to touch locations outside it, at greater access cost. An omitted storage key is therefore not automatically a forbidden read. The list describes anticipated work and changes its gas accounting; it is not an exhaustive boundary around what the transaction can touch.
