Wallet addresses
Base wallet address format
A Base address is an Ethereum-style address: the same format and the same string as on Ethereum. What that means when paying ETH or USDC on Base, with an example from the EIP-55 specification.
What a Base address looks like
| Fact | Base |
|---|---|
| Starts with | 0x |
| Length | 42 characters |
| Characters | hexadecimal (0–9, a–f) |
| Checksum | optional mixed-case checksum (EIP-55) |
| Example (Account address) | 0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed |
The example is taken from Ethereum Improvement Proposals, “ERC-55: Mixed-case checksum address encoding”, not from any account of ours or of a customer.
How a Base address is built
An EVM address is the last twenty bytes of a hash of the account’s public key, written as forty hexadecimal characters after “0x”. Upper and lower case carry no information on their own; the optional mixed-case form (EIP-55) spells some letters in capitals as a checksum, so a wallet that understands it can refuse a mistyped address. An address written entirely in lower case is valid and simply carries no checksum.
The same address is valid on every EVM network: Ethereum, Base, Polygon, BNB Chain and Lisk all read it. That is convenient and dangerous in equal measure — the address does not name a network, so the invoice must, and a payment sent on the wrong one lands on the same address on a chain the recipient may not be watching.
Using it on Base
On Base this address receives ETH and USDC. Unheld names the network on every invoice; send on that network, not on another EVM network where the same address also exists.
Check an address
Paste an address into the checker to see which family and format it is and whether its checksum holds. It reads the format only; nothing is looked up and nothing is stored.
Questions about Base addresses
What does a Base wallet address look like?
Forty hexadecimal characters after “0x”, forty-two in all. It may be written in lower case or in the mixed-case checksum form; both name the same account.
Is a Base address the same as an Ethereum address?
Yes. Base uses the Ethereum account format, so one address works on both — and on Base, Polygon, BNB Chain and Lisk. The network a payment travels on is chosen by the sender, so always send on the network the invoice names.
Why do some letters in my address appear in capitals?
That is the EIP-55 checksum. A wallet that understands it can detect a mistyped address. An address with no capitals is still valid; it simply cannot be checked that way.
Sources
Every figure on this page comes from one of these documents. Each was read on the date shown rather than recalled.