Joint borrower insurance: how to choose your coverage split

Why coverage split matters for joint borrower insurance

When you buy a property as a couple, the question is not only whether to buy or rent, but also how to share the borrower insurance between both borrowers. This sharing is called the coverage split (in French, quotité d’assurance). It determines:

• the level of protection each partner gets in case of death, disability or loss of income,
• the total cost of insurance over the life of the loan,
• the couple’s financial resilience if something goes wrong.

With mortgage rates around 3.6% and insurance rates (taux_assurance) often between 0.25% and 0.45% per year, the way you split coverage can change your total cost by many thousands of euros over 20–25 years. Before even deciding to buy or rent, understanding this lever is crucial.

What is a coverage split in joint insurance?

The coverage split is the percentage of the loan amount insured on each borrower. For a couple, the total split must be at least 100%, and can go up to 200%.

Typical split structures

• 50% / 50%: both borrowers are insured on half of the loan each.
• 70% / 30%: one borrower has higher coverage than the other.
• 100% / 100%: each borrower is insured on the full loan (double coverage).

If a covered event occurs (death, total disability, etc.), the insurer repays the share of the outstanding balance that corresponds to the insured share of the affected borrower.

Simple simulation: direct impact of the split

Assume a home loan of €300,000 over 25 years at a loan rate of 3.6%, with a borrower insurance rate (taux_assurance) of 0.30% on the initial principal.

• Annual insurance cost at 100% total coverage: €300,000 × 0.30% = €900/year.
• Over 25 years (no renegotiation): €900 × 25 = €22,500.

With a 50% / 50% split:

• Each borrower is insured on €150,000 → €450/year each.
• Total cost remains €900/year, but the protection is evenly shared.

With 100% / 100% double coverage (same taux_assurance):

• Each borrower is insured on €300,000 → €900/year each.
• Total cost: €1,800/year, or €45,000 over 25 years.

The coverage split is therefore not just a legal detail: it is a core financial parameter, on par with the interest rate or loan term, and must be part of any serious buy or rent analysis.

How the split shapes your financial safety

Scenario 1: 50% / 50% split

You buy as a couple, each insured at 50%. If one partner dies:

• the insurer repays 50% of the outstanding balance,
• the survivor must continue repaying the remaining 50%.

Example: outstanding balance at the time of death: €240,000.

• Paid by insurance: 50% × €240,000 = €120,000.
• Still owed by the survivor: €120,000.

If the survivor’s income is strong, this may be manageable. If not, the surviving partner may be forced to sell the property, which undermines the long-term buy or rent strategy you initially had in mind.

Scenario 2: 70% / 30% split

This is common when one partner earns significantly more or pays a larger share of the monthly instalment. If the 70% borrower dies:

• Insurance repayment: 70% × €240,000 = €168,000.
• Remaining debt for the survivor: €72,000.

The survivor’s burden is much lighter than with 50/50, for a moderate extra cost if the taux_assurance is similar for both borrowers.

Scenario 3: 100% / 100% split

Each borrower is insured for 100% of the loan. If one partner dies:

• the insurer repays 100% of the outstanding balance,
• the survivor has no mortgage instalments left to pay.

This is maximum protection: your main home is fully secured for the surviving partner. But the insurance cost doubles. You need to compare that extra cost with your other goals (investments, children’s education, renovations) and with your long-term buy or rent positioning.

Coverage split and taux_assurance: two sides of the same coin

The insurance rate (taux_assurance) depends on age, health, smoking status, job, sports, etc. In a couple, it is very common for both borrowers to have different insurance rates.

Example: two very different risk profiles

Take the same €300,000 loan over 25 years:

• Borrower A: 32 years old, non-smoker, employee, taux_assurance = 0.22%.
• Borrower B: 45 years old, smoker, higher-risk job, taux_assurance = 0.50%.

Cost with a 50% / 50% split:

• A: €150,000 × 0.22% = €330/year.
• B: €150,000 × 0.50% = €750/year.
• Total insurance: €1,080/year, i.e. €27,000 over 25 years.

With a 70% (A) / 30% (B) split:

• A: €210,000 × 0.22% = €462/year.
• B: €90,000 × 0.50% = €450/year.
• Total insurance: €912/year, i.e. €22,800 over 25 years.

You save €4,200 over the loan term while giving more protection to A (often the main earner). But B is less covered. This is exactly the kind of trade‑off a buy or rent simulator can highlight when it lets you adjust the taux_assurance and coverage split for each partner.

Financial logic: coverage vs cost vs investing

Choosing your coverage split is essentially an arbitration between:

• Immediate cost: higher total coverage (towards 200%) means higher annual premiums.
• Long‑term risk: lower coverage on one borrower means the survivor carries more of the loan if something happens.
• Global wealth strategy: money not spent on insurance can be invested (ETFs, savings, pension funds) instead of going into extra coverage.

On a €300,000 project:

• Difference in cost between 100% / 100% and 50% / 50% at 0.30% taux_assurance: about €22,500 over 25 years.
• If those €900/year were invested at a 4% annual return instead (investment rate), they could grow to roughly €42,000 after 25 years.

Depending on your situation, it may be better to:

• pay for double coverage (100% / 100%) to fully secure the family home, or
• keep total coverage at 100% (e.g. 70% / 30%) and invest the savings in financial assets.

There is no universal answer, just as there is no one‑size‑fits‑all answer to buy or rent. It depends on your incomes, existing wealth, risk tolerance and long‑term plans.

Practical criteria to choose your split as a couple

1. Relative income weight

• If one partner earns 70% of the household income, their loss would severely hit the budget.
• A split like 70% / 30% or 80% / 20% often makes more sense than 50/50.

2. Job stability

• Permanent contract vs self‑employed, risk of unemployment, income volatility.
• The less stable income may justify higher coverage for that partner.

3. Existing assets

• Emergency savings, ETF portfolio, pension savings, other properties.
• If you already have significant assets, you may feel comfortable with a total split of 100% instead of 200%.

4. Age and health

A big age gap or health issues usually mean a higher taux_assurance for one borrower. Should you reduce their coverage to cut costs, at the risk of leaving them less protected?

5. Life plans and holding period

• Do you plan to keep this home for 20+ years, or is it a 7–10 year stepping stone?
• Will you possibly rent it out later instead of selling?

On a shorter horizon, the cumulative cost of insurance is lower, but coverage still matters a lot if you have children or a big loan amount.

Full worked example: comparing coverage splits

Project: main residence for €350,000, with 7% notary fees (existing property). You pay €50,000 down and borrow €320,000 over 25 years at 3.6%.

Two borrowers:

• A: 35 years old, taux_assurance = 0.25%.
• B: 38 years old, taux_assurance = 0.35%.

Scenario 1: 50% / 50%

• A: €160,000 × 0.25% = €400/year.
• B: €160,000 × 0.35% = €560/year.
• Total insurance: €960/year → €24,000 over 25 years.

Scenario 2: 70% (A) / 30% (B)

• A: €224,000 × 0.25% = €560/year.
• B: €96,000 × 0.35% = €336/year.
• Total insurance: €896/year → €22,400 over 25 years.

You save €1,600 vs 50/50, while protecting A more (likely the main earner), and protecting B less.

Scenario 3: 100% / 100%

• A: €320,000 × 0.25% = €800/year.
• B: €320,000 × 0.35% = €1,120/year.
• Total insurance: €1,920/year → €48,000 over 25 years.

Compared to 50% / 50%, full double coverage costs an extra €24,000 over the loan term. You must weigh this against:

• your need for security (children, single income risk),
• other homeowner costs: property tax, maintenance, energy upgrades,
• potential investment returns if that money was invested instead (investment rate).

Integrating coverage split into the buy or rent decision

In a comprehensive buy or rent comparison, borrower insurance and the taux_assurance are often overlooked. Yet they:

• directly affect your actual monthly payment,
• change the total cost of ownership,
• influence how much you could save and invest if you kept renting.

A tool like the buy-or-rent.net simulator lets you:

• test different coverage splits (50/50, 70/30, 100/100),
• set the taux_assurance for each partner based on age and health,
• compare the buy scenario (with insurance, property tax, renovation) to the rent scenario (rent indexed to inflation, capital invested).

That way, your decision is not based only on “rent vs mortgage payment”, but on a complete cash‑flow and risk picture.

Key checks before locking in your split

• Read the policy details: what exactly is covered (death, disability, loss of work), exclusions, waiting periods.
• Check if you can adjust the split later: marriage, separation, career change may justify changing the coverage.
• Compare providers: bank insurance vs external insurers, impact on taux_assurance and coverage quality.
• Factor in other homeowner costs: rising property tax, building charges, energy‑efficiency works required by regulation.

All of these influence how sustainable your mortgage is and, therefore, what coverage split is truly appropriate for your couple.

Conclusion: no “right” split, only the one that fits you

Just like the decision to buy or rent, there is no universally “best” coverage split for joint borrower insurance. A 50% / 50%, 70% / 30% or 100% / 100% split can all be rational, depending on:

• your respective incomes and stability,
• family situation and dependants,
• existing assets and investments,
• risk appetite and long‑term plans.

The numerical examples above show how the taux_assurance and coverage split can swing the total cost of your loan by tens of thousands of euros, while deeply changing your safety net if something happens to one partner.

This article is for information only and does not constitute personalised financial advice. To decide which coverage split suits you and see how borrower insurance fits into your overall buy or rent strategy, you need to run the numbers with your own data.

Simulate your situation on buy-or-rent.net