Kast Sonic Card, explained: USDC on Sonic, costs and getting money out

The Kast Sonic Card is the KAST Visa card funded with USDC sent over Sonic. KAST takes USDC on Sonic with no KAST fee and credits it 1:1 as dollars. Sonic is deposit-only, so withdrawals leave on Arbitrum, Solana or Ethereum.

What is the Kast Sonic Card?

The Kast Sonic Card is the regular KAST Visa card, topped up with USDC sent over Sonic, the EVM chain that took over from Fantom. There is no separate card: Sonic is one of the 13 networks in KAST's deposit list.

It suits people whose USDC already sits on Sonic, from DeFi or from an exchange that pays out there. If your USDC is somewhere else, Solana, Base or Arbitrum are usually simpler.

KAST Receive stablecoin screen with coin, network, QR code and address
Kast Sonic Card: pick USDC, then the network

How to deposit USDC on Sonic to KAST

USDC is the only coin KAST takes on Sonic:

  1. In the KAST app, tap Receive and choose Stablecoin.
  2. Pick USDC, then Sonic from the network list.
  3. Copy the address with the copy button.
  4. Send USDC on Sonic from your wallet or exchange to that address.

KAST charges nothing and credits it 1:1 in dollars. At least $1 has to arrive after network fees. If you're new, our Kast Card sign up page covers opening the account.

KAST app USDC balance with Deposit and Withdraw buttons
Kast Sonic Card: USDC balance after a deposit

Sonic, not Fantom, and no S tokens

Sonic and Fantom Opera are separate chains, and some wallets still show both. KAST lists Sonic only. Pick Sonic on the sending side and check that the coin is USDC.

Sonic's own S token isn't on KAST's convert list either. If your balance is in S, swap it to USDC on Sonic before you send.

What Sonic costs with KAST

A USDC deposit on Sonic is free on KAST's side; you only pay Sonic's gas, which the sending wallet shows before you confirm. Card payments in US dollars are free and other currencies carry a 0.5% to 1.75% FX fee.

Every other charge, from ATM withdrawals to bank payouts, is on our Kast Card fees page.

Phone payment approved at a card terminal on a restaurant table
Kast Sonic Card payment approved at a terminal

Getting money out when Sonic is deposit-only

KAST doesn't send out on Sonic. USDC can leave on Arbitrum ($0.20 + 0.1%), Solana ($1 + 0.1%) or Ethereum ($6 + 0.1%), with a $5 minimum.

Arbitrum is the cheapest and works with the same 0x wallets you use on Sonic. Our Kast Arbitrum Card and Kast Solana Card pages cover both routes.

Spending Sonic USDC with the Kast Card

Once the USDC lands it is a dollar balance you can spend anywhere Visa works. Cashback is paid in US dollars: up to 8%, with 1.5% on the free Standard tier and more on the paid tiers.

KAST: send in crypto, spend in stables
Kast Sonic Card: send crypto, spend stablecoins
Black KAST Visa card tapped on a card reader
Kast Sonic Card at a card reader
KAST USD cashback by tier: 1.5%, 2% and 3%
Kast Sonic Card cashback by tier

Kast Sonic Card referral code: 6MHGEMGE

The referral code for the Kast Sonic Card is 6MHGEMGE. It works whatever network you fund with: $20 after your first $100 of card spend and 10% off a paid membership. Sign up through app.kast.xyz/referral/6MHGEMGE and it is added for you.

6MHGEMGE Sign up with the code →

The conditions for each reward are on our KAST referral code page.

Information only, not financial advice. This site is independent and not operated by KAST. Network facts from KAST Concierge (supported stablecoins, tokens and blockchains, fees) and KAST's posts on X, checked Oct 2026. Images: KAST on X.