Why USDT TRC20 Transfers Fail With "Out of Energy"
OUT_OF_ENERGY is the single most common reason a USDT transfer fails on TRON, and it has nothing to do with your USDT balance.
What Energy actually pays for
Every TRC20 transfer, including USDT, is a smart contract call under the hood, and smart contract calls on TRON are paid for with a resource called Energy rather than a simple flat fee. A standard USDT transfer to an address that already holds USDT costs roughly 65,000 Energy. Sending to a brand-new address that has never held USDT costs closer to 130,000, since the contract also has to activate storage for that address.
Why your wallet ran out
Energy is only free if you've staked (frozen) TRX for it, or someone has delegated Energy to your address. Without that, TRON falls back to burning TRX directly from your balance to cover the same Energy cost. If your TRX balance is too low to cover the burn, the transaction fails with OUT_OF_ENERGY instead of just being expensive.
How to fix it
Keep roughly 30-60 TRX available in any wallet you use to send USDT — that's usually enough buffer for several transfers even without staking. For frequent senders, freezing TRX for Energy removes the recurring cost entirely. Use the energy calculator on this site to check exactly how much you're short before retrying.