“Buy crypto” is not one button. Three stages, and each has its own way to lose money.

1. Fiat onto a CEX

You register on an exchange, pass KYC, buy USDT/USDC. That is a custodial account. While the stable sits there, the keys are not yours.

2. Withdraw to your wallet

You install a non-custodial wallet. You copy the address from it, not from a chat. On the exchange withdrawal you pick the same network as the wallet.

  • EVM (Ethereum, Base, Arbitrum…): 0x address, ETH for gas.
  • Solana: Phantom address, SOL for gas.
  • TON: Tonkeeper, TON for gas.

Wrong network — often zero, not “support will refund”.

3. Swap on-chain

You need a token the exchange does not list, or you simply do not want to keep it on the CEX: