Japan Mortgages: Flat 35, Variable Rate Spreads, and Housing Loan Tax Deduction

An authoritative guide to Japanese mortgages: JHF Flat 35 fixed-rate financing, bank variable-rate screening, the 125% repayment buffer rule, and the 0.7% housing loan income tax credit.

Updated 2026-09-06 · Audited against Japan Housing Finance Agency (JHF) and Ministry of Land, Infrastructure, Transport and Tourism (MLIT) guidelines. · Fact-Checked Lending Norms

Flat 35 government-backed fixed loans (JHF)

The Japan Housing Finance Agency (JHF), in partnership with private banks, provides Flat 35 (フラット35)—a fixed-rate mortgage for up to 35 years. Properties must meet strict earthquake resistance and energy conservation (Shoene) criteria. Debt Service Ratios (DSR) are legally capped at 30% for annual incomes under 4 million JPY, and 35% for incomes of 4 million JPY and above.

Bank variable rates and the 5-year / 125% rule

Over 70% of Japanese home buyers choose ultra-low variable mortgages. Under Japanese banking practice, variable loans feature the '5-year rule' (Gonen Rule: monthly repayments remain unchanged for 5 years regardless of rate hikes) and the '125% rule' (any repayment increase at the 5-year reset cannot exceed 125% of the previous payment).

Housing loan tax credit (Jutaku Loan Kojo)

Homeowners qualify for an annual income tax credit equal to 0.7% of their year-end mortgage balance for up to 13 years on certified eco-friendly homes (maximum qualifying debt of 30M to 50M JPY depending on environmental tier and construction year). Unused credits offset local resident tax (Juminzei).

Ancillary purchase costs (Shohiyo)

Budget approximately 6% to 8% of property value for transaction costs: real estate acquisition tax (Fudosan Shutokuzei), registration license tax, revenue stamps, loan guarantee fees (Hoshoryo), and statutory real estate agent brokerage commissions capped at 3% + 60,000 JPY + consumption tax.

ℹ️ Statutory Notice & Methodology

Global Finance Calculator provides mathematical estimates for education, planning, and comparison — not regulated financial advice or credit pre-approval. Tax legislation, statutory central bank buffers, and underwriting criteria change. Confirm critical figures with official regulatory publications or a licensed mortgage broker before signing contracts.