USDT
USDT is one dollar with 10 separate lives. The token on Tron and the token on Ethereum are both worth a dollar and are both called USDT, but on-chain they are unrelated credits. An address expecting one will not receive the other, and no amount of explaining afterwards moves the money back. Choosing the standard is the whole job; everything else is a transfer.
The standard is the recipient’s choice, not yours
Whoever is receiving the money decides which chain they can credit. An exchange that asked for TRC20 will not find a BEP20 deposit, because it is not looking at that chain. When someone gives you an address, ask which network it is for. The address alone does not always tell you, since every EVM chain uses the same 0x format.
Where it is cheapest to sit
Tron and BNB Chain carry the bulk of USDT because they are cheap to move it on. Ethereum is the most expensive and the most widely accepted. The rollups sit in between. Since this wallet pays the network fee out of the transfer, the practical difference is smaller here than it is elsewhere: you are choosing for the recipient, not for your own gas balance.
The version on Arbitrum
Arbitrum carries the LayerZero edition, tickered USDT0. It is the same dollar and the wallet shows it as plain USDT, deliberately: a second name for one asset is how a balance ends up priced correctly on one screen and at zero on another.
Moving between them
Going from one chain’s USDT to another is a genuine cross-chain move, quoted as one number with the network fee inside it. BNB Chain to Tron, the most asked-for pair, is $1 of network fee instead of $3, with no energy rental at the far end.
Networks carrying USDT
Questions
What happens if I send TRC20 USDT to an ERC20 address?
It stays on Tron, at an address whose owner may or may not control the Tron side of it. It is not converted and it does not bounce. This is why the network is asked for before the address.
Which USDT network is cheapest?
Tron and BNB Chain are the cheapest to move on. In this wallet the fee is inside the quoted amount either way, so the more useful question is which one your recipient can credit.
Why does Arbitrum USDT have a different ticker elsewhere?
Arbitrum carries USDT0, the LayerZero edition of the same dollar. The wallet shows one name for it so prices and balances agree across every screen.
What does moving USDT between chains cost?
One amount in USDT, with the network fee already inside it. BNB Chain to Tron is $1 of network fee instead of $3.