Key Points
・On October 3, 2026, Yuichiro Tamaki, leader of the Democratic Party for the People, pointed out that the most common rate on Flat 35, Japan’s main fully fixed-rate mortgage, had reached 3.830%, the highest under the current system. He proposed adding an interest subsidy to the existing mortgage tax credit.
・A fixed rate is set when you borrow, while a variable rate moves after you borrow, following the Bank of Japan’s policy rate. The same “rising rates” headline therefore lands differently on people about to buy and on people already repaying.
・No one can say for certain whether fixed or variable will turn out cheaper, or when the next rate hike will come. What a household can check is how its own contract works, its remaining balance and term, and the monthly payment it can actually sustain. Preparation starts there.
Tamaki Cites Record Flat 35 Rate and Proposes an Interest Subsidy
On October 3, 2026, Yuichiro Tamaki, leader of the opposition Democratic Party for the People, posted on X that the most common October rate on Flat 35, the fully fixed-rate mortgage backed by the Japan Housing Finance Agency, had reached 3.830%, the highest level under the current system. He attached an estimate: on a 30 million yen loan over 35 years, a rise from 2.0% to 3.83% adds about 30,000 yen to the monthly payment and about 12.8 million yen in interest over 35 years.
Tamaki said that Japan’s current mortgage tax credit deducts 0.7% of the year-end loan balance from income tax regardless of the interest rate, so higher rates are not reflected in the relief. He said his party would propose a mechanism such as an “interest subsidy” in addition to the tax credit, ahead of the year-end tax reform discussions.
In a follow-up post that evening, Tamaki explained that Flat 35 is a fully fixed-rate mortgage and that he was not proposing that “the government compensate for rises in variable rates.” He said who would be covered, how fixed and variable loans would be treated, and any income limits or subsidy rates were questions of policy design that still needed debate.
According to the Japan Housing Finance Agency’s October 2026 rate page, the most common Flat 35 rate (with the agency’s new group credit life insurance, a loan-to-value ratio of 90% or less and a term of 21 to 35 years) was 3.830%, up 0.37 percentage points from September’s lowest rate of 3.460%. The agency’s figure for December 2025 was 1.97%. On September 18, the Bank of Japan announced that it had raised its policy rate from around 1.0% to around 1.25%.
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How Fixed and Variable Mortgages Work in Japan
Flat 35 is a long-term, fully fixed-rate mortgage that private lenders offer in partnership with the Japan Housing Finance Agency, a government-affiliated institution. Each lender sets its own Flat 35 rate every month, and the agency collects and publishes them. Most Japanese borrowers, however, choose variable rates instead, as the survey cited below shows.
A fixed rate is set when you borrow; a variable rate is set after
With a fully fixed-rate mortgage, the interest rate for the entire term is decided when the loan is taken out. Once the contract is signed, the rate and repayment schedule agreed at that time do not change when market rates move. Changes built into the contract from the start, such as the end of an initial rate discount, can still occur.
A variable-rate mortgage is reviewed periodically after the loan begins. At many Japanese banks, the benchmark is the short-term prime rate, the rate banks charge creditworthy companies for loans of under a year, and it moves with the Bank of Japan’s policy rate.
After the September hike, MUFG Bank announced on September 18 and Sumitomo Mitsui Banking Corporation announced on September 28 that they would raise their short-term prime rates by 0.25 percentage points in November.
Counting the end of negative interest rates in March 2024, the Bank of Japan has raised rates six times to reach around 1.25%, according to its policy statements. Fixed rates rose first, and variable rates are following behind. According to the Japan Housing Finance Agency’s January 2026 survey, 75% of people who took out a mortgage between April and September 2025 chose a variable rate.
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Japan Raised Rates to a 31 Year High and the Yen Fell Anyway
What does a 30 million yen mortgage cost at different rates?
The table below changes only the interest rate on a 30 million yen loan over 35 years. It assumes level payments of principal and interest (the monthly payment stays the same), no bonus repayments, a rate that stays fixed for the full term, and no fees or insurance.
| Annual rate | Monthly payment | Total interest over 35 years |
|---|---|---|
| 1.3% | 88,945 yen | about 7.36 million yen |
| 2.0% | 99,379 yen | about 11.74 million yen |
| 3.0% | 115,455 yen | about 18.49 million yen |
| 3.83% | 129,791 yen | about 24.51 million yen |
Sekahan’s calculation using the standard level-payment formula. 3.83% is the most common Flat 35 rate in October 2026 published by the Japan Housing Finance Agency, 2.0% is the example in Tamaki’s post, and the other rows are for comparison.
In Sekahan’s October 2026 estimates, the gap between 2.0% and 3.83% is about 30,000 yen a month and about 12.77 million yen in total interest over 35 years. The table is not a forecast of future variable rates; it is a hypothetical comparison that changes only the rate under identical conditions. Borrowers who are already repaying can get their own figures by recalculating with their current balance and remaining term.
How variable-rate payments in Japan are reset
The rate a variable borrower actually pays is the bank’s posted “standard rate” minus a discount fixed at the time of the contract. When the standard rate rises, the rate paid rises by the same amount. When rates are reviewed and how changes are applied differ by bank and product, and are set out in the contract or product description. According to a Nikkei report on September 30, 2026, the lowest variable rates at major banks for October ranged from around 1.2% to 1.7%.
Many contracts with level payments, common at major banks, include two Japan-specific safeguards. Under the “5-year rule,” the monthly payment stays the same for five years even if the rate rises. Under the “125% rule,” when the payment is reset in the sixth year it can rise to no more than 1.25 times the previous payment. According to MUFG Bank’s FAQ, these rules apply to its variable-rate loans with level payments but not to those with equal principal payments. According to PayPay Bank’s FAQ, its mortgages have neither rule.
While the payment is frozen, a growing share of each payment goes to interest and the principal shrinks more slowly. If interest exceeds the payment, the excess is carried forward as “unpaid interest,” and anything still outstanding at the end of the term is, as a rule, due in a lump sum. The 125% cap applies to the monthly payment, not to the interest rate or the total amount repaid.
Fixed-period loans are recalculated when the period ends
A “10-year fixed” loan and similar fixed-period products lock in the rate only for the chosen period. When it ends, the borrower chooses again between fixed and variable. The new payment is recalculated from the balance, the remaining term and the rate at that time, so if rates have risen during the period, the payment rises to match.
Some of these contracts do not carry the 125% cap found on variable loans. MUFG Bank’s mortgage terms state that the variable-rate caps do not apply when payments are reset at the end of a fixed period. The word “fixed” is shared, but this is a different product from a fully fixed-rate mortgage.
Refinancing and prepayment have costs and trade-offs
Refinancing from variable to fixed involves administrative fees, guarantee fees, registration costs and other charges. A Sumitomo Mitsui Banking Corporation column puts the total, as of July 2024, at roughly 300,000 to 1 million yen. A new lender also requires new group credit life insurance, known in Japan as *danshin*, which repays the balance if the borrower dies or meets certain other conditions, similar to mortgage life insurance. Depending on health, a borrower may not be able to refinance.
Prepayment comes in two forms: shortening the remaining term, or lowering the monthly payment. Both reduce interest because the principal falls, but both reduce cash on hand. According to the National Tax Agency, Japan’s mortgage tax credit requires a repayment period of at least 10 years, and if prepayment brings it below 10 years, the credit is no longer available from that year onward.
Building a Plan From Your Contract and Your Household Budget
How much mortgage can you afford if rates keep rising?
What a bank will lend and what a household can keep paying are different numbers. According to the Japan Housing Finance Agency’s Flat 35 eligibility criteria as of October 2026, a borrower with an annual income of 4 million yen or more meets the standard if annual repayments are 35% or less of income. That is a ceiling on borrowing, and what each household can keep paying is a separate question.
For buyers choosing a variable rate while rates are rising, one approach is to calculate the payment after a rise, not at today’s rate, and set the budget by whether that payment can be met without cutting education costs or savings.
For example, by Sekahan’s estimates in the table, a rise from 1.3% to 3.0% adds about 27,000 yen a month. A fully fixed loan keeps the rate and repayment schedule agreed at signing, but it starts from a higher rate than a variable loan does today. Which turns out cheaper depends on future rates, and that cannot be known at the time of borrowing.
The Financial Services Agency’s life plan simulator and the Japan Housing Finance Agency’s loan calculator let households test repayments against projected income and spending. When property prices are high, it is tempting to borrow the maximum, but setting the budget at a level that can survive higher rates leaves more options later.
What can borrowers with variable-rate loans check before payments change?
For a variable-rate borrower, there are three things to confirm: the month when the rate is next reviewed, whether the contract freezes the payment under the 5-year and 125% rules, and how much of each monthly payment goes to principal and how much to interest, as shown in the repayment schedule. For a fixed-period loan, knowing the year and month the fixed period ends, and the balance and remaining term at that point, gives a sense of the recalculated payment.
Preparation offers more options if it starts before payments rise. Setting aside the difference between the current payment and a higher one now can smooth the jump when a payment freeze ends. Prepaying principal is another option, but using up savings leaves little room to respond if income falls.
If repayment looks likely to become difficult, borrowers can consult their lender before falling behind. The Japan Housing Finance Agency and private banks offer options such as extending the repayment period. These require screening and are at the lender’s discretion, and more options remain open when the borrower asks before missing a payment than after. An extension is something a borrower applies for; it does not happen automatically.
Is switching to a fixed-rate mortgage worth it?
Refinancing into a fixed rate works like insurance: the payment rises now in exchange for stopping future increases. By Sekahan’s estimates in the table, the gap between 1.3% and 3.83% is about 41,000 yen a month. That figure assumes a new 30 million yen loan over 35 years; for an existing loan, the payment is recalculated from the current balance, the remaining term and the rate actually offered.
The comparison that matters is the difference in interest over the remaining term against the total refinancing costs, together with whether the borrower can qualify for new group credit life insurance.
The case for and against Tamaki’s interest subsidy
There are reasons to support Tamaki’s proposal. According to the Ministry of Land, Infrastructure, Transport and Tourism, the mortgage tax credit is set at 0.7% regardless of the interest rate, so higher rates are not reflected. The point that a system designed for low rates is still running in an era of heavier interest payments is consistent with how the system developed.
There are also reasons for caution. On X, the proposal was first widely read as using taxpayers’ money to rescue people who chose variable rates, and Tamaki responded the same evening that it was not about compensating variable-rate rises. Questions remain about fairness toward existing borrowers and renters, funding, and the risk that support is priced into housing costs. By easing household burdens, a subsidy could also support demand and partly offset the effect of rate hikes. How large these effects would be depends on the design.
Who would be covered, and how fixed and variable loans would be treated, has not been decided, and the debate ahead of the year-end tax reform has yet to begin in earnest. Whatever the outcome, household finances are already moving before then. For those who have checked their contract and budget first, any new system becomes an additional support rather than the plan itself.
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Japanese Reactions to Tamaki’s Mortgage Interest Subsidy Proposal
These are posts on X and do not represent Japanese public opinion. The translations are by Sekahan, handles are omitted, and like counts are rounded figures displayed at the time of checking.
Among the quote posts we checked, most of the widely shared reactions opposed the proposal. The two most-liked ones read it as a plan to rescue borrowers who had chosen variable rates. One argued that a variable loan bundles the benefit of low rates with the risk of rising ones, and that compensating only the downside would leave the upside risk with society and the benefit with the individual. The other asked why people who chose a variable rate by contract would be rescued at all.
私、玉木さんのこと好意的だけど、これには賛同できない。… https://t.co/Lfg7YAPHyL
— 投資OL社長ちゃん (@OL20225358) October 3, 2026
I’m favorable toward Mr. Tamaki, but I can’t agree with this. A variable-rate loan is a product where you take on the benefit of low rates together with the risk of future rate rises. People who wanted to avoid the risk of rising rates also had the option of a fixed rate. Even so, compensating with public money only when rates rise could create an asymmetric system where “the upside risk falls on society and the downside benefit goes to the individual.”
Investment OL Shacho-chan, October 3, 2026 (roughly 3,200 likes, excerpt, translated by Sekahan)
Tamaki’s original post was about Flat 35, a fully fixed-rate loan, and that evening he added that the proposal was not about compensating rises in variable rates. Posts pointing out the misreading also appeared, but they spread far less than the first wave of criticism.
Other objections did not depend on that misreading. Some argued that funding interest payments with taxes works against the market and shifts the cost to taxpayers or future generations. Others said that because people who take out mortgages tend to have higher incomes, the subsidy would be regressive, or that a new system would hide the interest rate that new borrowers ought to feel.
Some posts moved to a different question. One proposal was to restore the tax credit rate from 0.7% to 1%, since it had been cut on the grounds that the credit exceeded the interest many borrowers paid at very low rates. Another argued that support aimed only at people who buy homes distorts the market, and pointed instead to the quality of the housing stock and town planning, including fairness toward renters.
そもそも住宅ローン控除率0.7%を1.0%に戻すべし。
— モノリス・キャピタル (@monorisujp) October 3, 2026
金利低下局面で、控除額が支払利息を上回るから0.7%に下げます、という話だったが金利が戻ったため、現時点で1％に戻さないロジックはあまりない。… https://t.co/7Agn4qTdmE
The mortgage tax credit rate of 0.7% should simply be put back to 1.0%. The rate was cut to 0.7% on the grounds that, while rates were falling, the credit exceeded the interest people paid. Now that rates have come back, there’s little logic in not returning it to 1% at this point.
Monolith Capital, October 3, 2026 (roughly 980 likes, excerpt, translated by Sekahan)
住宅ローン減税のような分譲住宅を買った人「だけ」救おうとするから市場が歪むのです。国がやるべきことは劣悪で陳腐な住宅の増加を防ぎ、良質な住宅ストックの形成と高環境かつ安全安心のまちづくりの誘導を行うことです。 https://t.co/tdYootnd3q
— 公団ウォーカー 照井啓太 (@codanwalker) October 3, 2026
The market gets distorted because policies like the mortgage tax credit try to help “only” people who bought homes. What the government ought to do is prevent the growth of poor-quality, outdated housing, build up a stock of good-quality homes, and guide the creation of safe, secure towns with a good living environment.
Keita Terui, October 3, 2026 (roughly 990 likes, translated by Sekahan)
Supportive voices were fewer and spread less. They argued that the personal responsibility of borrowers and a system that has not caught up with the times are separate issues.
玉木さんの指摘は的を射ている。
— 船乗り投資家 (@Tyyyaaabbb) October 3, 2026
3000万円を35年で借りた場合、金利2％なら利息は約1174万円、3.83％なら約2451万円。
差は約1280万円、月々も約3万円増える。ところが住宅ローン減税は年末残高の0.7％で、金利そのものは控除額に反映されていない。… https://t.co/DaHOkRvWgQ
The personal responsibility of those who borrowed and the problem of a system that hasn’t kept up with the times are separate issues. Proposing to consider easing the burden, including interest subsidies, in the tax reform is not an election ploy but a discussion grounded in the reality of household finances. I hope they take it all the way to a concrete plan by the end of the year.
Seafarer Investor, October 3, 2026 (roughly 130 likes, excerpt, translated by Sekahan)
These observations are based on searches at one point in time and do not measure the overall balance of opinion.
Read Your Contract Before Predicting Rates
For people about to buy, the news that Flat 35 has reached the 3.8% range is a real number they will face. For people already repaying a variable loan, when and how much it hits depends on each contract. No one can say for certain whether fixed or variable will win, or when the next hike will come. What can be checked is the type of contract, when it is reviewed, the remaining balance and term, and whether the household can bear a higher payment.
Tamaki’s proposal raises a fair question about adapting housing support to an era of positive interest rates, and both sides of the debate have reasons. The policy debate will run to the end of the year, but checking a household’s own contract can begin today. Rather than trying to predict rates, rereading the contract may be the more reliable form of preparation. What would your payment look like if your rate rose by one or two points?
Frequently Asked Questions
Will my monthly payment rise immediately if Japan’s variable mortgage rates go up?
Not always. According to MUFG Bank’s FAQ, its variable-rate loans with level payments keep the monthly payment unchanged for five years and cap the reset at 125% of the previous payment, although interest still accrues at the new rate. According to PayPay Bank’s FAQ, its mortgages have no such rules, so the rules in each contract decide when payments change.
Does the Flat 35 rate rise affect people who already have a Flat 35 loan?
No. Flat 35 is a fully fixed-rate mortgage, so the rate and repayment schedule agreed at signing do not change when market rates move, according to the Japan Housing Finance Agency. The 3.830% figure for October 2026 applies to new loans, and changes scheduled in the original contract can still occur.
How much more does a 30 million yen mortgage cost at 3.83% than at 2.0%?
About 30,000 yen more per month and about 12.77 million yen more in interest over 35 years, according to Sekahan’s calculation for a 35-year loan with level payments, no bonus repayments and a constant rate. For an existing loan, the figures depend on the current balance and remaining term.
How did Japanese social media react to the mortgage subsidy proposal?
Most widely shared reactions on X opposed it, and the two most-liked quote posts criticized it as a rescue for variable-rate borrowers, a reading Tamaki rejected the same evening. Other posts raised fairness toward renters, regressive effects, and restoring the tax credit rate to 1%, while supportive voices were fewer.
Sekahan on YouTube
We publish video summaries of articles like this one, along with short clips built around Japanese reactions.
Reference Links
- Interest Rate Information (Japanese) | Japan Housing Finance Agency (Flat 35)
- Flat 35 Interest Rates for December 2025 (Japanese, PDF) | Japan Housing Finance Agency
- Monetary Policy Decisions, September 18, 2026 (Japanese, PDF) | Bank of Japan
- Mortgage Tax Credit (Japanese) | Ministry of Land, Infrastructure, Transport and Tourism
- About the 5-Year Rule and 125% Rule for Variable Rates (Japanese) | MUFG Bank
- Does PayPay Bank Have a 5-Year Rule or 125% Rule? (Japanese) | PayPay Bank
- The Downsides of Refinancing a Mortgage (Japanese) | Sumitomo Mitsui Banking Corporation
- Prepayment (Japanese) | Japan Housing Finance Agency
- No.1225 Mortgages Eligible for the Housing Loan Tax Credit (Japanese) | National Tax Agency
- Changing Your Repayment Method (Japanese) | Japan Housing Finance Agency
