Japan's Debt-Servicing Costs Jump 17% to Record ¥36.6 Trillion

Japan's debt bill is climbing faster than tax revenue, squeezing the budget of the world's most-indebted major economy.

Japan's debt-servicing costs are set to jump 17 percent to a record ¥36.6 trillion in fiscal 2027, as rising long-term yields and an expansionary budget strain the world's most-indebted major economy.

The Finance Ministry plans to earmark the record sum for principal and interest payments on government bonds in its fiscal 2027 budget request, the Nihon Keizai Shimbun reported, with the assumed interest rate used to calculate bond costs rising to 3.8 percent from 3.0 percent.

The 10-year Japanese government bond yield climbed to 2.945 percent on Aug. 18, a near 30-year high, while Japan's debt-to-GDP ratio stood at 204.4 percent last year, the highest among major advanced economies.

The rising costs threaten to crowd out growth investment and welfare spending, and could reinforce a vicious cycle in which fiscal deterioration pushes rates higher, further swelling the debt bill.

The ¥5.3 trillion increase over the fiscal 2026 initial budget is the largest single-year jump in two decades, according to the Nikkei. The higher assumed rate reflects inflation, expectations of additional Bank of Japan rate hikes, and concern about fiscal discipline under Prime Minister Sanae Takaichi's expansionary stance.

Total budget requests from ministries and agencies for fiscal 2027 are projected to exceed ¥130 trillion, up from ¥122 trillion this year and a fourth consecutive record, Kyodo News reported. Takaichi has described the budget as marking "the first year of responsible, proactive fiscal policy," but the new growth-investment category carries no spending cap, leaving room for the final figure to expand further.

The funding gap is widening. New financing needs for next year's budget are expected to exceed ¥10 trillion, while the Cabinet Office estimates fiscal 2027 tax revenue at ¥90.5 trillion, an increase of just ¥6.8 trillion from the current year. That shortfall means the government will likely keep borrowing to cover the difference.

A Vicious Cycle Takes Hold

The bond market is already pricing in the strain. The 10-year JGB yield's climb toward 3 percent — the highest in about three decades — raises the cost of new issuance and refinancing, while low-yielding bonds issued during years of ultra-low rates mature and roll over at higher coupons. Nikkei noted interest costs could rise further as that refinancing wave builds.

Inflation is adding to the pressure. Japan's core-core CPI, which strips out fresh food and energy, rose 1.9 percent year on year in July, the first acceleration in nine months, the Financial Times reported. That strengthens the case for the Bank of Japan to lift its policy rate to 1.25 percent at its September meeting, a move that would push borrowing costs higher still.

The last time Japan's long-term yields approached current levels was in the mid-1990s, before the Bank of Japan's zero-rate era, when the government's debt burden was a fraction of today's. The debt-to-GDP ratio has since more than doubled, leaving less room for rates to rise without compounding the fiscal strain.

What's at Stake

Debt-servicing costs would absorb nearly 30 percent of the ¥130 trillion budget request, leaving less for growth investment, welfare, and defense. The Takaichi cabinet's priorities — including higher defense spending and a temporary cut to the food consumption tax — require more than ¥10 trillion in new financing, according to the report.

The risk of an external default remains low because most of Japan's debt is yen-denominated and held by domestic investors, including the Bank of Japan and Japanese financial institutions. But the pressure cycle between fiscal expansion, rising borrowing costs, and shrinking fiscal space may eventually force consolidation or further monetary tightening, with spillover effects on global bond markets and the yen.

This article is for informational purposes only and does not constitute investment advice.