How is the loan cap decided?

For 2024–25 occupancy: new build + certified (LTQ / low-carbon) → JPY 45M (JPY 50M with child-rearing); ZEH-grade → JPY 35M (JPY 45M); energy-code → JPY 30M (JPY 40M); other (no energy rating) → out-of-scope. Existing homes: certified / ZEH / energy-code → JPY 30M; other → JPY 20M. Anything borrowed above the cap is excluded from the credit calculation.

What's the credit rate and window?

Always 0.7%. Each year's year-end balance (capped) × 0.7% = that year's raw credit. The window is 13 years for new / dealer-resale builds and 10 years for existing homes.

What happens to credit beyond my income tax?

Spills into the resident tax (applied to next year's resident-tax bill). The resident-tax credit is capped at the smaller of 'taxable income × 5%' and JPY 97,500/yr. This tool uses only the JPY 97,500 cap as an approximation, which can over-estimate the credit for low-income filers.

What counts as 'child-rearing / young-couple'?

(a) you have a dependent under 19, OR (b) either spouse is under 40 (MLIT / NTA joint definition). Bumps the new-build cap by JPY 5M–10M. No effect on existing homes — the tool toggles its effect only when 'new build' is selected.

Does a 50-year term still qualify?

Any term ≥ 10 years qualifies. Flat-50 or 40/50-year private mortgages are fine — the credit window stays at 13 years (new) or 10 years (existing). The tool accepts up to 50 years.

Are floor area / income requirements modelled?

Floor 50 ㎡+ (or 40 ㎡+ with total income ≤ JPY 10M), total income ≤ JPY 20M, 10+ year term, owner-occupancy — all are assumed met by this tool.

What about prepayments?

Prepayments lower the year-end balance, which reduces the credit. This tool assumes the equal-payment schedule with no prepayments. Use a dedicated prepay simulator (coming later) to see the tradeoff.

The tool runs the entered rate flat for the whole term. Floating-rate borrowers face rate resets every 5 years; for a tighter estimate, run separate 'rate hike' scenarios.

Is my input uploaded?

No. Everything runs in your browser — principal, rate, term and income figures never leave the device.

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Japan mortgage tax credit estimator — 2024–25 caps, 13-year 0.7%

Estimate the Japanese housing-loan tax credit for 2024 / 2025 occupancy. Borrow caps depend on the property class — new build (LTQ / ZEH / energy-code / other) or existing (energy-class / other) — and on whether the household qualifies as 'child-rearing or young couple' for the higher cap. The tool runs an equal-payment amortization, applies the cap to each year-end balance, multiplies by 0.7%, and stretches over 13 years (new) or 10 years (existing). Any unused income-tax credit spills into the resident-tax credit (JPY 97,500 / year max). Runs entirely in your browser — loan details never leave the device.

financetaxcalculator

How to use

Pick new build vs. existing, then the energy class (certified / ZEH / energy-code / other). For new builds, also toggle the child-rearing / young-couple flag if applicable. Then enter principal (loan after down payment), annual rate, term (10–50 years), and the annual income tax (optional). Click Estimate credit to see (1) the cap inferred from class + household, (2) the credit window (13y new / 10y existing), (3) the equal-payment monthly amount, (4) the year-by-year balance, capped balance, raw credit, income-tax credit, resident-tax credit and applied credit, and (5) the period totals.

FAQ

How is the loan cap decided?: For 2024–25 occupancy: new build + certified (LTQ / low-carbon) → JPY 45M (JPY 50M with child-rearing); ZEH-grade → JPY 35M (JPY 45M); energy-code → JPY 30M (JPY 40M); other (no energy rating) → out-of-scope. Existing homes: certified / ZEH / energy-code → JPY 30M; other → JPY 20M. Anything borrowed above the cap is excluded from the credit calculation.
What's the credit rate and window?: Always 0.7%. Each year's year-end balance (capped) × 0.7% = that year's raw credit. The window is 13 years for new / dealer-resale builds and 10 years for existing homes.
What happens to credit beyond my income tax?: Spills into the resident tax (applied to next year's resident-tax bill). The resident-tax credit is capped at the smaller of 'taxable income × 5%' and JPY 97,500/yr. This tool uses only the JPY 97,500 cap as an approximation, which can over-estimate the credit for low-income filers.
What counts as 'child-rearing / young-couple'?: (a) you have a dependent under 19, OR (b) either spouse is under 40 (MLIT / NTA joint definition). Bumps the new-build cap by JPY 5M–10M. No effect on existing homes — the tool toggles its effect only when 'new build' is selected.
Does a 50-year term still qualify?: Any term ≥ 10 years qualifies. Flat-50 or 40/50-year private mortgages are fine — the credit window stays at 13 years (new) or 10 years (existing). The tool accepts up to 50 years.
Are floor area / income requirements modelled?: Floor 50 ㎡+ (or 40 ㎡+ with total income ≤ JPY 10M), total income ≤ JPY 20M, 10+ year term, owner-occupancy — all are assumed met by this tool.
What about prepayments?: Prepayments lower the year-end balance, which reduces the credit. This tool assumes the equal-payment schedule with no prepayments. Use a dedicated prepay simulator (coming later) to see the tradeoff.
Floating rate?: The tool runs the entered rate flat for the whole term. Floating-rate borrowers face rate resets every 5 years; for a tighter estimate, run separate 'rate hike' scenarios.
Is my input uploaded?: No. Everything runs in your browser — principal, rate, term and income figures never leave the device.

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