Obtaining a mortgage loan relies less on the perceived quality of one’s profile than on the compliance of the application with specific criteria, largely dictated by the High Council for Financial Stability (HCSF). Understanding these criteria, their interplay, and the actual margins available to banks allows one to gauge their chances even before stepping into a lending institution.
Debt ratio and usury rate: two thresholds that lock down mortgage credit
Two ceilings currently frame access to mortgage loans. The first is the maximum debt ratio of 35%, including borrower insurance, imposed by the HCSF since January 1, 2022. The second is the usury rate, which includes not only the nominal rate but also the processing fees and the cost of insurance.
The trap of the usury rate is often underestimated. A nominal rate that seems reasonable can push the APR beyond the legal threshold once additional fees are added. The application is then automatically rejected, with the bank unable to make exceptions.
| Criterion | Threshold | What it includes | Consequence in case of exceeding |
|---|---|---|---|
| Debt ratio (HCSF) | 35% | Monthly payment + borrower insurance / net income | Rejection unless an exception (limited quota) |
| Usury rate (Banque de France) | Variable depending on the loan duration | Nominal rate + insurance + processing fees + guarantee | Automatic rejection, no exceptions possible |
These two filters do not operate in the same way. The debt ratio allows for some flexibility: banks can deviate from the HCSF criteria within the limit of 20% of their quarterly credit production. In the second quarter of 2026, the use of this flexibility reached 18.1%.
Almost all of the available margin is therefore already consumed. A borrower who exceeds the 35% threshold should not base their financing plan on the assumption of an exception.
To compare offers and simulate your borrowing capacity, a dedicated tool for mortgage credit on Quartier Immo allows you to confront several financing scenarios before submitting an application to the bank.
Mortgage duration and total cost: the trade-off that simulators obscure
The recent trend described by several sources is one of extending the duration of mortgage loans. Lengthening the duration mechanically reduces the monthly payment, making it easier to fall below the 35% debt threshold.
The effect on the total cost is less visible. Each additional year generates extra interest. For the same borrowed amount, shifting from a short duration to a long duration can significantly increase the total amount of interest paid, sometimes by several tens of thousands of euros.
Reduced monthly payment versus increased total cost
Online simulators emphasize the monthly payment. They rarely display the total cost of credit in such a clear manner. Before choosing a duration, it is relevant to compare the cumulative cost of interest across several repayment scenarios.
A borrower with a repayment capacity slightly above the minimum monthly payment has an interest in shortening the duration rather than maintaining “monthly comfort.” The difference in total cost is often disproportionate compared to the savings of a few tens of euros per month.
Preparing a mortgage application: the elements that banks truly weigh
Beyond the debt ratio, banking institutions evaluate the application on several axes that do not all carry the same weight.
- The stability of income takes precedence over its absolute amount. A permanent contract with several years of seniority weighs more than a high income from a temporary contract or during a trial period.
- The personal contribution reduces the borrowed amount and the risk for the bank, but it also plays a role in negotiating the rate. A contribution that at least covers the ancillary costs (notary, guarantee) is generally expected.
- The management of bank accounts over the last three to six months is scrutinized. Recurring overdrafts or online gambling expenses can be enough to undermine an otherwise correct application on paper.
- The remaining disposable income, that is, the amount left after paying the monthly payment and fixed charges, is a common-sense criterion that each bank calculates according to its own internal scales.
Borrower insurance: an underutilized cost lever
Borrower insurance is included in the calculation of the debt ratio and the usury rate. Choosing an alternative insurance policy rather than the group contract proposed by the bank can sufficiently reduce the APR to allow an application that would otherwise be rejected.
The law allows changing borrower insurance at any time. This lever is particularly useful when the application is at the limit of the usury rate.
Zero-interest loan and complementary loans: real eligibility conditions
The zero-interest loan (PTZ) remains a scheme reserved for the purchase or construction of a primary residence, with resource and geographical location conditions. Its amount only covers a fraction of the total financing.
Other complementary loans exist: Action Logement loan for employees of contributing companies, loans from local authorities depending on the territories. Combining several subsidized loans reduces the share of traditional bank credit and mechanically improves the debt profile.
The recent decline in credit activity shows that banks are lending less. In this context, an application that combines a contribution, a PTZ, and a competitive delegated insurance stands out clearly from an application relying solely on a traditional long-term bank loan. The criterion that distinguishes two borrowers with comparable profiles remains the ability to reduce the overall APR by optimizing each component of the financing.
