WBTC input identity and handling
Wrapped Bitcoin is classified as a wrapped asset for this route. WBTC uses a wrapped contract asset on Scroll. The recorded Scroll representation uses 8 decimal places. WBTC leaves through a custodial wrapper contract with token approval and source-chain gas; no native Bitcoin UTXO is spent by that transfer.
Scroll to Arbitrum L2 handoff
This route crosses two L2 execution environments. Scroll settles to ethereum, while Arbitrum settles to ethereum; each side keeps its own gas balance, token contracts, transaction hash, and settlement progress.
WBTC unwrap or exchange input check
WBTC is a custodial tokenized Bitcoin representation on smart-contract networks. Its transfers use token contracts and approvals rather than native Bitcoin inputs and outputs. On this route WBTC is the source token on Scroll. Its token balance, approvals, and contract transfer behavior are separate from the native coin used for network gas.
Arbitrum destination execution
Arbitrum is a L2 EVM network in the Ethereum ecosystem. ETH pays destination-side network gas on Arbitrum. EVM 0x account address An Arbitrum receipt appears on the Nitro L2 ledger under an Arbitrum token contract or native ETH balance; later spending needs Arbitrum ETH while L1 settlement continues separately.
ETH output identity and receiving
Ethereum is classified as a native asset for this route. ETH uses a native asset on Arbitrum. The recorded Arbitrum representation uses 18 decimal places. Determine whether ETH arrives as native destination gas or as a tokenized representation. Only the native balance can directly pay that network’s fees.
Scroll source execution
Scroll is a L2 EVM network in the Ethereum ecosystem. ETH pays source-side network gas on Scroll. EVM 0x account address A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently.
EVM-to-EVM execution boundary
Scroll and Arbitrum can use the same 0x address syntax, but they are separate networks with different chain identifiers, gas balances, token contracts, and transaction histories. The recorded settlement context includes ethereum, so L1 and L2 confirmation behavior should not be assumed identical.
Mistakes specific to WBTC Scroll to ETH Arbitrum
Route-specific mistakes include sending on a network other than Scroll; using a destination that is not valid for Arbitrum; running out of ETH before the source transaction is submitted; treating a wrapped token as the native gas asset. A Scroll source executes in the zkEVM and is later included in a proof batch to Ethereum; Scroll contract identity must be verified independently. WBTC leaves through a custodial wrapper contract with token approval and source-chain gas; no native Bitcoin UTXO is spent by that transfer. An Arbitrum receipt appears on the Nitro L2 ledger under an Arbitrum token contract or native ETH balance; later spending needs Arbitrum ETH while L1 settlement continues separately. Determine whether ETH arrives as native destination gas or as a tokenized representation. Only the native balance can directly pay that network’s fees.