Tax Classification and Rate Structure
As of 2026, profits from crypto trading by Japanese individual taxpayers are classified as 'miscellaneous income' and aggregated with salary and other income under progressive taxation. The marginal rate ranges from 5% to 45% (national income tax) plus 10% resident tax, for a combined maximum of 55%. By contrast, equities and FX enjoy a flat 20.315% separate taxation rate, putting crypto at a structural tax disadvantage. Legislative discussions on separate taxation for crypto are ongoing but not yet enacted.
Cost-Basis Calculation Methods
Two methods are permitted for calculating acquisition cost: total average method (divides total acquisition cost by total quantity at year-end) and moving average method (recalculates weighted average cost at each disposal). Total average is simpler but obscures mid-year P&L; moving average provides real-time accuracy. The chosen method must be maintained for at least three years. Notably, crypto-to-crypto swaps (e.g., BTC to ETH) constitute taxable disposals.
Taxation of Derivatives
Gains from perpetual futures and options are also classified as miscellaneous income. Funding income (as from cash-and-carry arbitrage) is taxed upon realization; unrealized gains on open positions are not taxed. Japanese residents must report gains from overseas exchanges (Binance, etc.) in their tax filings. While exchanges provide annual P&L reports, traders using multiple venues and DeFi protocols must self-aggregate, making comprehensive transaction logs essential.
Treatment of Losses
Losses within the miscellaneous income category can offset gains within the same category, but cannot offset income from other categories (equities, salary, FX). Carryforward of losses is not permitted, so a large gain in one year followed by a loss the next year offers no retroactive relief. This asymmetry limits tax-loss harvesting strategies for systematic traders. Intentionally closing positions at year-end to crystallize losses is technically valid but carries the risk of being challenged as lacking economic substance.
Record-Keeping and Filing
Required records include: (1) date, quantity, and JPY-equivalent price for every transaction, (2) trading fees, (3) funding received/paid, and (4) wallet-to-wallet transfers (for cost-basis tracking). USDT-denominated gains on overseas exchanges must be converted to JPY using the TTM rate (telegraphic transfer middle rate) at the time of each transaction. The National Tax Agency provides a free 'Crypto Calculation Worksheet,' but with thousands of annual trades typical of systematic strategies, dedicated tax-calculation tools (Cryptact, Gtax, etc.) are effectively mandatory. This article is for informational purposes only and does not constitute tax advice. Consult a qualified tax professional for specific tax decisions.