Arbitrum, Optimism and Base in Spain: taxes
L2 operations taxed same as mainnet: DEX swaps = capital gain/loss; staking = capital income; NFTs = same rules.
Bridging: Bridge ETH mainnet → Arbitrum = NOT taxable. Same asset, same acquisition cost, different network.
USDC.e vs native USDC: CCTP swap may or may not be taxable depending on treatment (equivalent vs swap).
L2 token airdrops (ARB, OP): Capital income at market value when received/claimed.
L2 fees: Lower than mainnet but same tax rules (small crypto spend).
kointax supports Arbitrum, Optimism, and Base.