Complementary loan
A complementary loan is a supplementary financing instrument added to the main mortgage to cover part or all of the remaining cost or unfinanced fees. It can take several forms: the zero-rate loan (PTZ), the action logement loan (PAL), savings-plan loan (PEL), employer loan, local-authority loan, or family loan. Combining them with the main mortgage is a core element of the financing plan a broker puts together.
Key points
- Assisted complementary loans (PTZ, PAL) have strict eligibility criteria (income ceilings, geographic zone, property type).
- They are always factored into the DTI calculation because they also generate monthly payments.
- The repayment ordering (which loan is repaid first?) is an optimization parameter in the financing plan.
- Some complementary loans offer full or partial deferred repayment periods, reducing the initial payment burden.
- The PTZ 2024–2025 has been refocused on high-demand zones for older properties requiring renovation work.
Frequently asked questions
How are complementary loan payments factored into the debt-to-income ratio?
Every monthly payment — from the main loan, the PTZ, the action logement loan, or an employer loan — is summed to form total debt service. This total is then divided by counted income to yield the overall DTI ratio. If some complementary loans are in full deferral, their payments do not count during the deferral period but enter the calculation once actual repayment begins.
How does a borrower find out if they are eligible for the PTZ in 2025?
PTZ eligibility rests on several cumulative criteria: not having owned a primary residence in the past two years (first-time buyer), meeting income ceilings based on household composition and geographic zone (A, A bis, B1, B2, C), and purchasing a new property or an older one requiring renovation work representing at least 25% of the total cost in zones B2 and C. The PTZ amount varies based on these same parameters.
What is the difference between an action logement loan and a standard employer loan?
The action logement loan (formerly '1% logement') is funded by compulsory contributions from companies with more than 50 employees. It offers a capped preferential rate (around 1% excluding insurance in 2025) and is subject to national eligibility criteria. A standard employer loan is granted directly by the company to its employees under its own rules, without involving Action Logement.
In practice
A first-time-buyer primary-school teacher purchases an older apartment in zone B1. Her broker builds a financing plan combining a main loan of €170,000 at 3.45% over 25 years, a PTZ of €60,000 over 20 years with a 5-year full deferral, and an action logement loan of €25,000 at 0.5%. The deferred PTZ reduces the combined monthly payment by €240 in the first five years, keeping her DTI ratio below the 35% threshold.
Official sources
- Obtaining a mortgage loan · Service-Public.gouv.fr
- Mortgage credit (official guide) · Service-Public.gouv.fr