→TRC-20 USDT is cheapest to transfer (<$1). Use for peer-to-peer and exchange deposits
→ERC-20 USDT needed for Ethereum DeFi — expect $2–20 gas fees
→Always verify the network BEFORE sending — TRC-20 address starts with T, ERC-20 with 0x
→Never store large USDT amounts on exchanges — use self-custody