USDD wallet

What is USDD (USDD)?

USDD is the dollar stablecoin of the TRON ecosystem, issued and managed by the TRON DAO Reserve. It started as an algorithmic coin in the mold of the early Terra design, where TRX was burned to mint USDD, and after that model fell out of favor it moved to an over-collateralized structure: USDD is now minted against locked collateral such as TRX and other reserve assets, and a peg stability module lets it be swapped one to one against USDT to hold the price near a dollar. The balance in a wallet does not change on its own; one USDD stays one USDD until it is sent or redeemed.

What a holder actually deals with

The home of USDD is TRON, where it is a TRC-20 token. Sending it costs energy and bandwidth, which means either staking TRX for resources or holding a little TRX to be burned as the fee. A wallet with USDD and no TRX cannot move the coin. On Ethereum and BNB Smart Chain the coin exists as an ERC-20 / BEP-20 token, and there the fee is paid in ETH or BNB respectively.

Two things trip people up. First, the move to the current collateralized version came with a new token contract: the previous token is labeled as the old USDD and can be converted to the current one, so a balance that shows up under a legacy name is not lost, it is the earlier contract. Second, on TRON the ticker sits one letter away from USDT, and both are TRC-20 tokens with the same fee mechanics, so an exchange withdrawal form is where the mix-up usually happens.

Because USDD spreads across chains, Tangem shows the network name on the transfer screen before the card signs, so you see whether the coin is leaving on TRON, Ethereum or BNB Smart Chain and can hold the matching fee coin alongside it in the same wallet. For a coin whose main hazard is the network rather than the coin itself, that is the check that matters most. Supported networks in Tangem (3): Ethereum, BNB Smart Chain, TRON.