Statutory definition

“Miscellaneous income means income that does not fall into any of the categories of interest income, dividend income, real estate income, business income, employment income, retirement income, timber income, capital gains, or occasional income.” (Income Tax Act, Article 35(1))

Where do profits from crypto trading belong for income tax purposes? The starting point is Article 35(1) of the Income Tax Act quoted above.

As you can see, the provision does not positively describe miscellaneous income. It merely lists nine income categories and saysincome falling into none of them. Miscellaneous income has no affirmative definition of its own.

Nor does the term “crypto assets” appear anywhere in this provision. Article 35(1) does not name crypto assets. Their income nevertheless reaches this category because the provision works by elimination. This structure is the first point to understand.

Overview

Why Is Miscellaneous Income Determined by Elimination?

The Income Tax Act divides income into ten categories: interest, dividends, real estate, business, employment, retirement, timber, capital gains, occasional, and miscellaneous. Each of the first nine has a positive definition. Miscellaneous income alone differs: Article 35(1) lists the other nine and ends with “income falling into none of them.”

Miscellaneous income is therefore the residual category. First consider whether income fits any of the nine; only after ruling them all out does miscellaneous income become the answer.

This is easily misunderstood for crypto assets. Saying “crypto income is miscellaneous income” can sound as if a provision expressly classifies it that way. No such provision exists. Rather, crypto trading gains are neither interest, dividends, real estate, employment, retirement, timber, capital gains, nor occasional income, leading to miscellaneous income through that reasoning.

Capital gains have prompted the most debate in this process. Looking only at the fact that an asset was sold at a profit, it appears to be income from an asset transfer. Asking why it is not capital gains is natural.

However, the wording of the Act's crypto provisions reveals a different legislative premise. We examine this next.

How Do the Provisions Position Crypto Income?

The Income Tax Act has one provision specifically naming crypto assets: Article 48-2, “Calculation of Crypto Asset Transfer Costs and Methods of Valuation.” It states:

“...when calculating amounts included as necessary expenses in that person's business income or miscellaneous income.” (Income Tax Act, Article 48-2(1))

It is a short passage, but notice the income categories listed.Only business income and miscellaneous income appear.Capital gains do not appear. Neither does occasional income.

Of course, Article 48-2 does not itself determine income classification. It specifies how necessary expenses are calculated through year-end valuation. Nevertheless, when addressing crypto necessary expenses, the Act names only business and miscellaneous income. Thus,the provision itself appears to envisage individuals' crypto income as either business or miscellaneous income.

The same wording recurs in the Enforcement Order.

• Article 119-4(2), applying inventory provisions to changes in valuation methods, substitutes “business income or miscellaneous income” for “business income.”
• Article 119-5(2), concerning reassessments or determinations by the tax office director, refers to “the resident's business income or miscellaneous income for each year.”
• Article 119-7, concerning settlement of crypto margin transactions, refers to “amounts included as necessary expenses in that person's business income or miscellaneous income for the year.”

Both the Act and Order consistently list business and miscellaneous income when addressing crypto assets. This consistent wording is the strongest clue to their classification.

Which of the two applies? The provisions do not state the dividing standard. Article 48-2 and the Order simply place both categories side by side without defining the boundary. Miscellaneous income is the principal treatment for many individuals, but the line for activities conducted as a business does not emerge directly from this wording. It is accurate to recognize that these provisions do not supply that answer.

What Does Aggregate Taxation Mean?

For miscellaneous income, the calculation is:

“...gross revenue from miscellaneous income during that year (excluding public pensions and similar income), less necessary expenses.” (Income Tax Act, Article 35(2)(ii))

Miscellaneous income is revenue minus necessary expenses. That is straightforward; the issue comes afterward.

Miscellaneous income is subject to aggregate taxation: the year's income is combined before tax rates are applied. Employees combine salary income with crypto miscellaneous income; business owners combine it with business income. Income tax rates rise progressively as the combined amount increases.

This affects the actual burden. The additional tax on the same JPY 1 million profit varies with the person's other income. Crypto profit cannot be isolated and assigned a tax amount independently; the full year's income is needed.

Timing creates another practical difficulty. Crypto prices can move sharply late in the year. Large profits near year-end increase total annual income and affect the applicable progressive rate. Without forecasts during the year, taxpayers may struggle to fund tax payments when filing season arrives.

Your own burden must be assessed individually using all income for the year.

What Is Expected to Change?

The explanation so far describes the current statutory framework. That framework is expected to change.

The FY2026 Tax Reform Outline proposed, for certain crypto transfers and similar transactions, a move toseparate assessment taxationat 20%. This changes direction from combining crypto income with other income under aggregate taxation to taxing it separately.

For details, eligible crypto assets, and commencement, see Key points of the FY2026 tax system revision outline Please see

Remember that the outline is a Cabinet-approved policy, not itself a legal basis for taxation. Treatment changes only after its contents are enacted and take effect. Until then, the quoted provisions continue to apply. Separate reports of a future separate-tax regime from the treatment of transactions taking place now.

Points that require care in practice

• Exchanging crypto assets for other crypto assets rather than selling them. This raises the question of whether income arises without receiving yen.
• Paying for goods or services with crypto assets. Even if viewed simply as shopping, the disposal of crypto assets must be considered.
• Receiving crypto through mining, staking, or lending. Two stages need to be distinguished: valuation on receipt and treatment upon later sale.
• Receiving crypto without payment through an airdrop or hard fork. Determining acquisition cost is the issue.
• Receiving compensation or salary in crypto assets. Classification of the receipt and treatment of later price movements are separate questions.
• Whether income is business or miscellaneous income. Because the provisions do not state the boundary, the question is where to find the basis for judgment.
• Treatment of losses in the year. The relationship with other income requires separate review of the provisions and reforms.
• The same crypto type held across multiple exchanges or wallets. The question is the unit over which total average or moving average is applied.
• Using overseas exchanges. Different transaction record formats make annual aggregation itself more demanding.
• No valuation-method notification filed. Article 119-5(1) requires total average, but you should establish which method you have actually used.

Legal basis

• Income Tax Act, Article 35(1) (Miscellaneous Income) / Quoted wording: “Miscellaneous income means income that does not fall into any of the categories of interest income, dividend income, real estate income, business income, employment income, retirement income, timber income, capital gains, or occasional income.”
• Income Tax Act, Article 35(2)(ii) (Miscellaneous Income) / Quoted wording: “gross revenue from miscellaneous income during that year (excluding public pensions and similar income), less necessary expenses.”
• Income Tax Act, Article 48-2(1) (Calculation of Crypto Asset Transfer Costs and Methods of Valuation) / Quoted wording: “when calculating amounts included as necessary expenses in that person's business income or miscellaneous income.”
• Order for Enforcement of the Income Tax Act, Article 119-2(1) (Methods of Valuation of Crypto Assets) / Quoted wording: “total average method”; “moving average method.”
• Order for Enforcement of the Income Tax Act, Article 119-3(2) (Selection of a Crypto Asset Valuation Method) / Quoted wording: “Written notification of the method to be used among those in the preceding article's paragraph (1), for crypto assets of the same type, must be made to the tax office director having jurisdiction over the place of tax payment.”
• Order for Enforcement of the Income Tax Act, Article 119-4(2) (Procedure for Changing a Crypto Asset Valuation Method) / Quoted wording: “‘business income’ shall be read as ‘business income or miscellaneous income.’”
• Order for Enforcement of the Income Tax Act, Article 119-5(1) (Statutory Crypto Asset Valuation Method) / Quoted wording: “valuation at acquisition cost calculated using the total average method.”
• Order for Enforcement of the Income Tax Act, Article 119-5(2) (Statutory Crypto Asset Valuation Method) / Quoted wording: “where it is considered possible to calculate appropriately the resident's business income or miscellaneous income for each year.”
• Order for Enforcement of the Income Tax Act, Article 119-7 (Acquisition Cost of Crypto Assets in Margin Transactions) / Quoted wording: “amounts included as necessary expenses in that person's business income or miscellaneous income for the year.”
• Payment Services Act, Article 2(14) (Definitions) / Quoted wording: “property value usable for payment with unspecified persons and purchasable and saleable with unspecified counterparties”; “transferable using an electronic data processing system.”