Losses from early investment may reduce future Japanese corporation tax. But budgeting on the assumption that accumulated losses eliminate tax after profitability is risky. The usable amount is established through tax returns; deadlines, company classification and capital decisions affect how quickly it can be used. For founders, the key question is how much can be used in each year.

1. Accounting losses are different from usable tax losses

A loss in the income statement is an accounting loss. A corporation tax loss results from calculating taxable revenue and deductible expenses. Some accounting expenses are not deductible in the same year, so the amounts may differ. Software development expenditure, for example, may require capitalization and depreciation for tax even when expensed in the accounts. Begin with the amount after tax adjustments.

Suppose an illustrative company records an accounting loss of ¥20 million, has ¥6 million of expenses not deductible that year and has no other adjustments. Its tax loss is ¥14 million. Entering ¥20 million directly into a cash forecast overstates the amount available for future use by ¥6 million.

A tax loss balance is not cash that can be withdrawn. Carryforward relief reduces tax only when the loss offsets future taxable income. A ¥14 million loss carryforward is not a right to a ¥14 million refund. Keeping separate forecast lines for revenue, profit, taxable income, tax payments and cash helps avoid this confusion.

2. The ten-year period depends on filing and recordkeeping

The carryforward period for blue-return losses arising in fiscal years beginning on or after April 1, 2018 is ten years; for earlier fiscal years it is nine years. Conditions include a blue return for the loss year and consecutive subsequent final returns. Older losses are used first. This does not mean ten years from incorporation. NTA: Loss carryforwards

A particularly avoidable startup mistake is postponing tax filings because there are no sales. To obtain blue-return approval from the first fiscal year, the application is generally due on the day before the earlier of the date three months after incorporation and the end of that first fiscal year. A company incorporated close to its year-end may have less than three months. NTA: Notifications for newly incorporated companies

Keeping tax returns alone is not enough. Books and documents for eligible loss years generally require ten years of retention, or nine years for fiscal years beginning before April 1, 2018. NTA: Record retention periodsWhen changing accounting software or staff, transfer prior-year general ledgers, invoices, contracts and return data together. Avoid losing access when a software subscription ends.

3. The same loss balance does not always eliminate all taxable income

Qualifying small and medium-sized corporations and certain other entities can generally offset all pre-deduction income; the general limit for other corporations is 50%. Under the 50% limit, taxable income remains even if the loss balance is large enough. MOF: Overview of loss carryforwards

Assume an opening usable loss carryforward of ¥50 million, no expiry and no other adjustments. The table compares taxable income before applying tax rates, not tax payable.

For an ordinary stock company, capital of ¥100 million or less is a starting point for the small-company classification, but it is not the entire test. Certain companies wholly controlled by large corporations are excluded from small-company benefits. NTA: Wholly owned subsidiaries of certain large corporationsVC investment does not automatically impose the 50% limit. Examine the investor's legal form, direct and indirect ownership and capital after the fundraising.

Even companies outside the small-company category may qualify for full offset during certain fiscal years as newly established corporations. Eligible years contain a day within the period from establishment to the date seven years thereafter, with exclusions including certain wholly owned subsidiaries. Fiscal years ending on or after listing or the specified registration are excluded from this startup exception. NTA: Table for newly established corporationsNeither “capital exceeding ¥100 million immediately halves the deduction” nor “all companies under seven years old retain full offset after listing” is a reliable rule.

4. Put profitability, fundraising and listing on the same timeline

Overlay annual loss balances with profitability forecasts and capital plans. A useful schedule records the year each loss arose, its original amount, amounts already used, remaining balance and final usable fiscal year. Then add forecast income before deduction and the applicable annual limit. Where fiscal years change or short periods occur, counting remaining fiscal periods alone is not an adequate expiry calculation.

If the company subject to the 50% limit above earns another ¥30 million in the following year, its deduction will generally again be ¥15 million. It cannot necessarily use the full remaining ¥35 million at once. Separate scenarios for delayed profitability, an earlier IPO and a larger capital increase reveal potential tax funding gaps despite substantial losses.

Capital structure decisions require more than a loss calculation. A capital reduction does not necessarily restore every previous tax treatment; size-based enterprise taxation requires a separate analysis. See our related article on capital reductions and size-based enterprise tax. Compare the cash impact of alternatives without delaying commercially sensible fundraising solely for tax reasons.

5. Protect usability instead of assuming zero tax

For boards and investors, a three-year schedule of expected deductions and taxes is more useful than a single accumulated-loss figure. Ask the finance team to reconcile the forecast with Schedule 7(1) of the corporation tax return and ask the tax adviser to identify years when the company's classification changes. Maintaining annual schedules and supporting records throughout loss-making years is more reliable than reconstructing them after profitability.

This article addresses ordinary carryforwards in a continuing business. Acquisitions and reorganizations may trigger separate restrictions. Buying a company with losses does not make those losses freely available for tax savings. See tax losses of an acquired company. Our domestic tax consultation can help examine capital plans alongside tax payment forecasts.

Rules and sources checked as of October 31, 2026. Numerical examples are illustrative assumptions.