USDT representation on both sides
The input must match the selected ERC-20, TRC-20, SPL, or other USDT representation; each standard has different address, approval, and fee behavior. Confirm whether the output is ERC-20, TRC-20, SPL, or another USDT standard; a wallet supporting one standard may not credit another. The same stablecoin ticker does not make the two network records or contracts interchangeable.
ETH source gas and ETH destination readiness
A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger. An OP Mainnet receipt belongs to the OP Stack L2 and needs ETH on that network for later activity; it is not an Ethereum L1 balance.
Base to Optimism L2 handoff
This route crosses two L2 execution environments. Base settles to ethereum, while Optimism settles to ethereum; each side keeps its own gas balance, token contracts, transaction hash, and settlement progress.
Base deposit-side execution
Base is a L2 EVM network in the Ethereum ecosystem. ETH pays source-side network gas on Base. EVM 0x account address A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger.
Optimism receipt-side execution
Optimism is a L2 EVM network in the Ethereum ecosystem. ETH pays destination-side network gas on Optimism. EVM 0x account address An OP Mainnet receipt belongs to the OP Stack L2 and needs ETH on that network for later activity; it is not an Ethereum L1 balance.
Base to Optimism bridge mistakes
Route-specific mistakes include sending on a network other than Base; using a destination that is not valid for Optimism; running out of ETH before the source transaction is submitted; selecting a stablecoin by ticker without checking its network contract. A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger. The input must match the selected ERC-20, TRC-20, SPL, or other USDT representation; each standard has different address, approval, and fee behavior. An OP Mainnet receipt belongs to the OP Stack L2 and needs ETH on that network for later activity; it is not an Ethereum L1 balance. Confirm whether the output is ERC-20, TRC-20, SPL, or another USDT standard; a wallet supporting one standard may not credit another.