The multi-chain wallet problem
Stablecoins like USDC don't live on one blockchain — they live on several, and those blockchains largely don't talk to each other. Ethereum, Base, Polygon, and Arbitrum are all EVM-compatible, so a wallet built for one of them can usually handle the others too. Solana is a different architecture entirely, with its own address format and its own ecosystem of apps.
In practice, that means most people end up with two wallets, not one: something like MetaMask or a Base-native wallet for the EVM side, and something like Phantom for Solana. Each has its own address, its own seed phrase, and its own login. If a friend sends you USDC on Solana but your address on hand is an Ethereum address, the payment can't land — the formats aren't interchangeable.
None of this is a bug in any single wallet. It's just what happens when an app is built around one chain, and you end up living across several.
How FAX solves it
FAX gives you one account that spans all five chains at once: Ethereum, Base, Polygon, and Arbitrum on the EVM side, plus Solana. You log in once, with your email and a passkey, and see everything from there.
Your balances across all five chains aren't shown as five separate numbers you have to add up yourself. FAX combines them into a single number, so you can watch your portfolio grow without doing the math per network. It's the same underlying idea as checking one bank balance instead of tracking five different account statements.
Because FAX is self-custody, you hold the keys — there's no custodian sitting between you and your funds. But setup doesn't involve the part of self-custody most people dread: there's no seed phrase to generate, write down on paper, and hope you never lose. Your wallet is created with just an email address and a passkey.
A huge share of people who've used crypto wallets before have a story about losing access — a seed phrase written on a sticky note that got thrown out, a photo of twelve words that lived on a phone that broke. A passkey works differently: it's tied to your device's Face ID or Touch ID, the same mechanism that already unlocks your phone dozens of times a day. There's nothing to transcribe and nothing to lose in the same way.
How receiving and deposits actually work
Getting funds into FAX works two ways, depending on what you're receiving.
The first is a dedicated address per chain. Open the receive screen, pick the chain the sender is using — say, Base or Solana — and FAX shows you the exact address for that network along with a QR code. This is the direct route: the sender's USDC on that chain goes straight to your matching address on the same chain, the same way any same-chain transfer works.
The second is a broader deposit flow, and it's the one that covers the edge cases. Sometimes someone wants to send you a token, or is sending from a chain, that your main receive address wasn't set up to catch cleanly. Instead of that payment failing or landing somewhere you can't see, FAX's deposit flow can accept many different tokens from many different chains and convert them automatically — so what shows up in your FAX balance is USDC, regardless of what was actually sent or which network it came in on.
Between the two, you're covered whether you're sharing a precise address for a routine transfer or catching something less predictable.
Sending without needing gas tokens
Every blockchain transaction needs a small network fee — "gas" — paid in that chain's native token: ETH on Ethereum and Base, MATIC on Polygon, and so on. Normally, that means before you can send USDC on a given chain, you first need to separately acquire that chain's gas token, in the right amount, sitting in the right wallet. It's a strange requirement — you're moving dollars, but you need a different asset just to cover the toll.
Sending on FAX is gas-sponsored. You can send USDC without separately holding ETH, MATIC, or any other chain's native token just to pay the network fee. You send USDC, and that's the only balance you need to think about.
See your balances across every chain in one place
Open FAX and get one login for Ethereum, Base, Polygon, Arbitrum, and Solana.