Under the rules in force at the time of writing, gains on selling crypto assets are taxed as miscellaneous income under aggregate taxation: they are added to salary and other income and taxed at progressive rates of up to 55% (national and local tax combined). Not only outright sales but also exchanging one crypto asset for another, or paying for goods and services with crypto, count as disposals and are taxable. Cost basis is computed by the total-average method (or, on notification, the moving-average method). Losses can be offset only within miscellaneous income and cannot be carried forward. All of this has made crypto considerably more heavily taxed than listed shares (which enjoy 20.315% separate taxation). (See our note: Are You a Tax Resident of Japan?)
The 2026 reform and the 20% rate
That treatment is being revised by the 2026 tax reform. A separate self-assessed taxation regime for transfers of “designated crypto assets” has been enacted, with a flat rate of 20% (20.315% including the special reconstruction surtax).
When does the new regime start?
However, the start date is defined as “transfers on or after 1 January of the year following the year in which the amending Financial Instruments and Exchange Act takes effect”. It therefore tracks the FIEA amendment timetable and is not yet fixed. A start from January 2028 has been reported, but this could shift with the passage and implementation of the legislation.
What stays under aggregate taxation
The scope is also limited. Separate taxation will apply only to transfers of “designated crypto assets” made through registered domestic operators (spot transactions, plus derivatives and the ETFs expected to be launched). Sales through overseas exchanges, DEXs (decentralised exchanges) or private transactions, and mining or staking rewards, remain under aggregate taxation even after the reform. Once the regime applies, losses can be carried forward for three years, but they cannot be offset against gains on shares. Nor is there any equivalent of the designated-account withholding system used for shares: you compute your own gains and file a return. The same crypto sale can therefore be taxed under different regimes depending on the route the transaction takes.
Until the new regime starts
A practical caution: until the new regime starts, the current aggregate taxation continues. Sales, exchanges and payments made before then must be declared as miscellaneous income in the usual way. The precise scope of “designated crypto assets” and the start date will be settled by forthcoming legislation and official releases — check the latest position before you sell.
Crypto gains to declare?
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