In 2027, the maximum debt-to-income ratio remains set at 35% of your net income before tax, borrower insurance included, over a term of no more than 25 years. In practical terms, the bank adds up all of your loan repayments (the future mortgage, but also your car loan or any alimony you pay), then divides them by your regular income. If the result exceeds 35%, the application falls outside the framework, unless an exception is granted. The good news: this is not the only criterion. Your disposable income after expenses (the "reste à vivre"), the stability of your income, your down payment and the way you manage your accounts also weigh in the decision. In this guide, we explain the formula simply, what the bank really takes into account, and how to present an application that gets approved, even with rates of around 3.5% over 20 years.
In summary
- The 35% rule (insurance included) and the maximum term of 25 years apply to all banks following the decision of the Haut Conseil de stabilité financière (HCSF).
- Banks may grant exceptions for 20% of their applications, as a priority for primary residences and first-time buyers.
- The calculation is based on your regular net income before tax; exceptional bonuses and part of any rental income received are often reduced.
- With an average rate of 3.51% over 20 years in November 2026, a monthly payment of €1,400 corresponds to approximately €234,000 borrowed, excluding insurance.
- Pay off small loans, keep your accounts in good order and prepare your down payment before approaching the bank: this is often what makes the difference.
What exactly is the debt-to-income ratio?
Before talking numbers, let's lay the groundwork. The debt-to-income ratio (also called the "taux d'effort") measures the share of your income devoted to repaying your loans. It is the indicator the bank looks at first to determine whether your project is reasonable.
The calculation formula, simply put
The formula fits on one line: debt-to-income ratio = (total loan repayments, insurance included) / (total monthly net income) × 100. For example, a couple earning €4,000 net per month and repaying €1,300 per month for their future loan, plus €100 for a car loan, has a debt-to-income ratio of exactly 35%: 1,400 / 4,000 = 0.35. That is the limit.
Why 35% and not 33%?
For a long time, banks set themselves a limit of around 33%. Since 2021, the Haut Conseil de stabilité financière turned a recommendation into a legally binding standard from January 2022: 35% maximum, insurance included, and a maximum term of 25 years (27 years in certain cases, for example for new-build properties with a deferral linked to construction). These rules are still in force as 2027 approaches.
An indicator, not a foregone conclusion
The debt-to-income ratio provides a framework, but the bank does not stop at this figure. It also looks at what you have left to live on once the loan is paid, the nature of your income and your financial behaviour. Two households with the same ratio may therefore receive different answers.
Which income does the bank really take into account?
This is often where surprises arise: not all of your income "counts" in the same way. The bank looks for stable, regular and lasting income.
Salaries and regular income
Net salary before withholding tax (prélèvement à la source) is the basis of the calculation, over 12 months, including the 13th month if it is contractual. For an employee on a permanent contract (CDI) outside the trial period, this is the simplest case. Tenured civil servants are also viewed very favourably.
Bonuses, overtime and variable income
Exceptional bonuses or overtime are often taken into account only if they have been regular for several years, and sometimes as an average over two or three years. For a self-employed person, the bank generally looks at the average of the last two or three financial statements or tax assessments.
Rental income
If you already receive rent, most banks take into account only about 70% of it, to allow for vacancy and costs. For a planned rental investment, some banks also include part of the future rent, depending on their policy.
Benefits and maintenance payments
Family allowances or alimony received may be taken into account, but with caution, especially if they end before the end of the loan (for example, when children grow up).
And what about debts: what weighs in the calculation?
In the numerator of the formula, the bank adds up all of your repayment obligations. Some are obvious, others less so.
The future mortgage and its insurance
The monthly payment on the planned loan, including borrower insurance, makes up most of your obligations. That is why the cost of insurance matters so much: cheaper insurance, thanks to insurance delegation (délégation d'assurance), directly frees up borrowing capacity.
Existing loans
Car loans, consumer loans, vehicle leasing with a purchase option (LOA), student loans being repaid: everything is added up. Even an unused revolving credit line may be taken into account as a precaution. The rent you pay today, on the other hand, is not counted if it disappears once you buy your main residence.
Maintenance payments
Child or spousal support (pension alimentaire) that you pay is treated as a debt obligation, in the same way as a loan.
How much can you borrow in 2027 with 35%?
Let's turn to concrete examples, calculated using the average rates observed in November 2026 (3.51% over 20 years, 3.59% over 25 years), excluding insurance. Several brokers expect rates to keep rising toward 4% in early 2027: keep a margin.
Household net income | Maximum monthly payment (35%) | Capacity over 20 years (3.51%) | Capacity over 25 years (3.59%) |
|---|---|---|---|
€2,500 | €875 | approximately €144,000 | approximately €166,000 |
€3,500 | €1,225 | approximately €204,000 | approximately €234,000 |
€4,000 | €1,400 | approximately €234,000 | approximately €269,000 |
€5,000 | €1,750 | approximately €294,000 | approximately €338,000 |
The amounts factor in about €40 per month of insurance for a couple; they are orders of magnitude. To find out which property fits this budget, once notary fees have been deducted, also take stock of your current home: if you already own, a free online property valuation on Optimhome shows you in a few minutes the down payment that its sale could generate.
The impact of the loan term
Going from 20 to 25 years increases borrowing capacity by about 15%, but the total cost of the loan also rises significantly. It is a useful lever, to be used with full awareness of the consequences.
The effect of a rise in rates
At 4% over 20 years, the same €1,360 monthly payment excluding insurance finances only about €224,000, which is €10,000 less than at 3.51%. Hence the value of moving forward with your application without waiting.
Exceptions: when the bank can go beyond 35%
The rule is not entirely rigid. The HCSF allows each bank to make exceptions for 20% of its quarterly mortgage lending.
Who benefits first?
At least 70% of these exceptions must relate to the purchase of a main residence, and a share is reserved for first-time buyers. Buy-to-let investors therefore benefit less often from this flexibility.
The role of disposable income (reste à vivre)
A high-income household can exceed 35% while still keeping a comfortable reste à vivre, for example €3,000 per month after repayments. This is typically the profile for which a bank agrees to an exception. Conversely, a modest household at 34% may be turned down if its reste à vivre is too low.
Profiles that reassure lenders
Remaining savings after the purchase, foreseeable career progression, no overdraft, existing assets: these elements help secure an out-of-the-norm "yes."
How can you improve your debt-to-income ratio before meeting the bank?
The good news is that you can often gain several points in a few months, with a bit of organization.
Pay off small loans
A car loan of €200 per month "costs" about €34,000 of borrowing capacity over 20 years. Repaying it early using your savings, provided this does not deplete your down payment, can change the picture.
Reduce the cost of insurance
The Lemoine law allows you to choose and change your borrower insurance at any time. A cheaper delegated insurance policy reduces the monthly payment and therefore the debt-to-income ratio.
Adjusting the project
A slightly cheaper property, a neighbouring area, some renovation work to plan for: there are often alternatives. Browse the Optimhome property listings by filtering on your real budget, to discover properties you might not have thought of.
Making use of subsidised loans
The zero-interest loan (prêt à taux zéro), extended until 31 December 2027, or the 1% Action Logement loan reduce the overall monthly payment. The conditions of the PTZ are detailed on the official Service-Public.fr page.
Three profiles, three answers: some telling examples
Take Léa, a nurse on a permanent contract (CDI), earning €2,600 net per month, with no loans in progress. For a studio priced at €150,000, she borrows €140,000 over 25 years: her monthly payment of about €730, insurance included, puts her at around 28%. Her application goes through without difficulty. Karim and Julie, for their part, earn €4,200 together but repay €350 on a car loan: to reach 35%, their future loan cannot exceed €1,120 per month. By paying off the car loan with part of their savings, they gain nearly €70,000 of borrowing capacity over 25 years. Finally, Marc, an executive earning €7,000 net, is aiming for a 40% debt ratio for a family home: his remaining income after expenses (reste à vivre) of more than €4,000 per month makes him a good candidate for an exemption.
Remaining income after loan payments (reste à vivre), the second filter that is often overlooked
The reste à vivre is what is left each month once loan payments have been made. There is no legal threshold, but banks have their own benchmarks, often in the order of a few hundred euros per adult and per child, and more in large cities where the cost of living is higher. A couple with two children who would keep €1,200 of reste à vivre will have a harder time than a single person who keeps the same amount.
The mistakes that make an application fail even though it is "within the guidelines"
We regularly see applications at 33% being turned down. Here are the most common pitfalls.
Poorly managed accounts
Repeated overdrafts, online betting, bank incident fees: the bank generally analyses your last three statements. Three months of impeccable accounts before applying is a real plus.
An insufficient down payment
Even with a good debt-to-income ratio, many banks require that notary fees and guarantee fees be covered by the down payment, which amounts to roughly 8 to 10% of the price for older properties.
A recent professional situation
A probationary period in progress, a business created less than two years ago or a short-term contract make the application more fragile, even with a satisfactory debt-to-income ratio.
A poorly put-together project
A property without a credible valuation, renovation work that has not been costed or a vague timeline worry the bank. The better prepared your project is, the more reassurance you provide.
The practical tip
- Calculate your debt-to-income ratio yourself before the meeting: (loans + insurance) / net income × 100.
- Test your project with a rate 0.25 points higher than today's, to keep a margin in case rates continue to rise in early 2027.
- Request a delegated insurance quote before going to the bank: you will arrive with an insurance cost that is already optimised.
- Gather your last three payslips, two tax assessment notices and three months of clean statements.
- Keep a safety net of savings after the purchase: it reassures the bank almost as much as a down payment.
The professional's advice
"I often see buyers who focus on the 35% figure, whereas the bank looks at an application as a whole. A household at 34% with impeccable accounts, a down payment that covers the fees and a well-valued project will get through more easily than a household at 30% with overdrafts every month. My advice: before viewing properties, run a serious simulation, then view properties that match this budget, not the dream budget. You will save time, you will negotiate better, and you will arrive at the bank with an application that tells a coherent story. When rates are rising, this is even more true: preparation makes the difference."
Getting support to buy at the right price
A financeable project is, first and foremost, a well-sized project. Your real estate advisor knows the actual prices in their area and can steer you towards properties that fit your borrowing capacity, sparing you from falling in love with a house that is out of budget.
To discuss your project with a professional in your area, find an Optimhome real estate advisor near you: they will help you prepare your viewings and present a solid offer, backed by your financing plan.
Preparing a credible purchase offer
An offer accompanied by a bank simulation or a broker's certificate reassures the seller. In a market where 9 out of 10 sales are negotiated, this is often what gets your proposal accepted over another.
Conclusion
In 2027, the 35% rule remains the reference framework for obtaining a mortgage, but it doesn't tell the whole story of your application. Income taken into account, actual expenses, disposable income after expenses, down payment and account management: it is the whole picture that convinces the bank. With rates on the rise, prepare your application in advance, optimise your insurance, pay off small loans and aim for a property suited to your actual capacity. You will give yourself every chance of success.
And if someone around you is thinking of selling their home, you can recommend them to an advisor and be rewarded by becoming an Optimhome business referrer.
FAQ - Frequently asked questions
Does the 35% debt-to-income ratio include borrower insurance?
Yes. Since the HCSF's decision, the 35% ceiling is assessed with borrower insurance included.
Is my current rent taken into account?
No, if it disappears with the purchase of your main residence. It is, however, useful for showing the bank your ability to pay a regular monthly instalment.
Can you borrow over 30 years in 2027?
No, the maximum term is 25 years, extended to 27 years in certain cases with a deferral, for example for a new-build property or major renovation work.
Is a self-employed person's income taken into account?
Yes, generally based on the average of the last two or three years, which requires having at least two sets of annual accounts.
Can a debt-to-income ratio of 38% be accepted?
It is possible within the 20% of exemptions, especially for a main residence with comfortable disposable income after expenses.
Do family allowances count as income?
Some banks include them, others do not, or only partially. They are rarely decisive in the calculation.
Does the PTZ increase my borrowing capacity?
Yes, indirectly: being interest-free and often with a deferral, it reduces the overall monthly payment for the same amount financed.
Do I need to use a broker?
It is not mandatory, but a broker knows which banks are the most flexible depending on the profile and can negotiate the rate and insurance for you.
Author of the publication
Fabrice DOBROWOLSKI, Director of the Optimhome network
«Benefit from myexpert advice, based on many years of experience in real estate, to ensure the success of your buying or selling project. »
