Energy
Energy is primarily associated with smart-contract execution. USDT TRC20 transfers interact with a contract, so Energy is often the resource users look at before sending.
Bandwidth
Bandwidth is a separate network resource associated with transaction data. A transaction can still need Bandwidth even if it has enough Energy.
Renting Energy does not replace every network requirement. Check both the transaction estimate and your remaining TRX balance before confirming a transfer.
Which one should you prepare?
For a USDT TRC20 transfer, start by reviewing the wallet estimate for Energy. Then keep enough TRX to cover possible Bandwidth use or any resource shortfall. This is more reliable than assuming a fixed fee for every transfer.
Open Energy rental →Technical sources and verification
These references explain the protocol. TronZero package prices are service terms, not TRON network fees. Recheck the wallet estimate before signing.