Mortgage refinancing: watch out for early repayment penalties

Refinancing and early repayment penalties: why they matter

Mortgage refinancing looks attractive when interest rates fall or your income changes. But one line in your loan contract can flip the math: early repayment penaltiespenalite_remboursement parameter and it can completely change the result.

In France, these penalties are tightly regulated: they cannot exceed 3% of the outstanding principal or 6 months of interest, whichever is lower. On paper this seems simple, but on your specific loan the impact can be several thousand euros. A refinancing that looks profitable based on the rate alone can become a losing move once you add the penalty.

This article is not tailored financial advice. It gives you a numbers-based framework to factor penalties into your buy or rent decision and to use a simulator like buy-or-rent.net more effectively.

How early repayment penalties are calculated

The legal cap: 3% or 6 months of interest

For a standard French fixed-rate mortgage, the bank may charge a penalty when you repay early in full (which is what happens in most refinancings):

• Cap 1: 3% of the outstanding principal at the time of repayment.
• Cap 2: the equivalent of 6 months of interest on the amount repaid, at the loan rate.

The actual penalty will be the lower of these two amounts. In a buy or rent simulator, the penalite_remboursement field should reflect this calculation, otherwise the ownership vs renting comparison will be distorted.

Worked example of penalty calculation

Assume:

• Outstanding principal: €200,000
• Loan rate: 3.6% (roughly in line with current French market levels)

We compute:

• 3% of outstanding principal: 200,000 × 3% = €6,000
• 6 months of interest:
  • Annual interest: 200,000 × 3.6% = €7,200
  • 6 months = 7,200 / 2 = €3,600

The penalty will therefore be €3,600 (lower than €6,000). In the simulator, the penalite_remboursement parameter should be set to this amount if you want your refinancing calculation to be realistic.

Why penalties can wipe out the benefit of refinancing

A lower rate is not enough

Many households only look at:

• Old rate: say 4.5%
• New rate: say 3.6%

The drop looks appealing. But to know if refinancing is worth it in a buy or rent perspective, you must compare:

• Total interest saved thanks to the new rate
• Total cost of the operation: early repayment penalty, new bank fees, new guarantee (hypothèque/caution), possibly notary fees if you change the type of security, and even agency fees if this refinancing is part of a sell-and-buy chain.

If your early repayment penalty (penalite_remboursement) is for example €5,000 and your interest savings are only €6,000, the net benefit is very slim once you also consider the administrative hassle and potential risks (new insurance rate, longer term, new conditions).

Full example: refinancing with penalties

Case study:

• Original mortgage: €250,000 over 25 years at 4.5%
• Remaining term: 18 years
• Outstanding principal: roughly €210,000 (ballpark figure)

You consider refinancing at 3.6% over 18 years (same remaining duration).

Step 1: Early repayment penalty

• 3% of outstanding principal: 210,000 × 3% = €6,300
• 6 months of interest at 4.5%:
  • Annual interest: 210,000 × 4.5% = €9,450
  • 6 months = 9,450 / 2 = €4,725

Penalty charged: €4,725 (the lower cap). This is your penalite_remboursement to enter in the simulator.

Step 2: Potential interest savings

Simplified (order of magnitude):

• Interest remaining at 4.5% over 18 years: around €90,000
• Interest at 3.6% over 18 years: around €70,000

Gross saving: €20,000 of interest.

Step 3: Total refinancing cost

• Penalty: €4,725
• New bank fees: e.g. €800
• New guarantee (mortgage or guarantee fund): e.g. €2,000

Total cost: about €7,500.

Step 4: Net result

Net gain = 20,000 – 7,500 ≈ €12,500. In this scenario, despite a non-trivial penalite_remboursement, refinancing remains clearly positive from a pure interest-cost perspective.

But if rates had only dropped slightly (for example from 4.5% to 4.1%), the gross saving might fall to €8,000–€10,000, making the net gain marginal once the penalty is included.

How penalties affect the broader buy or rent strategy

Refinancing when you might sell soon

Refinancing is rarely an isolated decision. It’s often part of a bigger question: stay in your current home, sell and rent, or sell to buy another property. In a buy or rent framework, early repayment penalties appear at two stages:

• At refinancing: you pay a penalite_remboursement to close the old loan.
• At resale: if you repay the refinanced loan early again (because you sell after a few years), a new penalty may apply.

You could therefore pay penalties twice, which heavily changes the comparison between staying a homeowner and switching to renting while investing your capital (ETFs, savings, life insurance, etc.).

Example: keep the home vs sell and rent

Scenario:

• You have a property with €200,000 of mortgage remaining.
• You hesitate between:
  • Option A: refinance to lower your monthly payments and stay owner.
  • Option B: sell, repay the loan, become a tenant and invest the equity.

In the buy-or-rent.net simulator, the early repayment penalty (penalite_remboursement) must be accounted for in both options:

• Option A: penalty paid now to refinance.
• Option B: penalty paid at the time of sale if you have not already refinanced.

This cost comes on top of other major parameters:

• Notary fees (7–8% in existing property, 2–3% in new-build) if you later buy another home.
• Agency fees (around 3–5%) when you sell.
• Property tax and its annual increase if you remain a homeowner.
• The investment rate on your capital if you rent instead of owning (ETFs, savings accounts, life insurance, etc.).

A high penalite_remboursement can tilt the short-term result towards keeping the current situation (no move, no sale), even if, over a longer horizon, other variables (inflation, rent growth, property price trends) might favour a different choice.

When do penalties hurt the most?

At the beginning of the mortgage

Because penalties are based on outstanding principal and/or interest, they tend to be highest:

• In the early years of the loan, when the principal is still large.
• On loans with high interest rates (6 months of interest add up quickly).

Simple illustration:

• After 3 years, outstanding principal: €230,000 → 3% = €6,900
• After 15 years, outstanding principal: €120,000 → 3% = €3,600

At the same rate, the penalite_remboursement is almost cut in half. Refinancing often becomes more attractive after a few years, when the combination of remaining interest savings and lower penalty turns favourable.

On large mortgage balances

The bigger the loan, the more penalties weigh in your buy or rent analysis:

• €100,000 loan: 3% cap = €3,000
• €400,000 loan: 3% cap = €12,000

On a large mortgage, a poor estimate of the penalite_remboursement parameter in your simulator can shift the result by many thousands of euros, and therefore alter your strategic choice (keep owning, sell, rent and invest).

How to integrate penalties in your buy or rent simulations

Using the "penalite_remboursement" parameter correctly

In a tool like buy-or-rent.net, the penalite_remboursement parameter represents the total amount you pay your bank to close the existing mortgage early. To use it correctly:

• Check your original loan offer for the exact penalty clause.
• Estimate your outstanding principal on the planned refinancing date (amortisation schedule or request from your bank).
• Compute both caps (3% of principal, 6 months of interest) and keep the lower value.
• Enter that number in the penalite_remboursement field of the simulator.

You’ll then get a more reliable comparison between:

• No-refinance scenario: you keep your current loan.
• Refinance scenario: you pay the penalite_remboursement but benefit from a lower rate.

Compare penalties with other key inputs

Penalties should never be analysed in isolation. In a full buy or rent decision, you should also look at:

• The new mortgage rate (around 3.6% currently in France, depending on profile and term).
• The borrower insurance rate (typically 0.25–0.45%) which may change with the new loan.
• Notary fees if you plan to buy a different home.
• Property tax and its yearly revaluation if you continue to own.
• The annual rent increase (linked to the IRL index) if you become a tenant.
• Your expected investment return if you rent instead of owning (ETFs, cash, bonds, etc.).

It’s the combination of all these parameters, including penalite_remboursement, that gives you an objective view of your long-term cost of housing under different buy or rent scenarios.

Best practices before signing a refinancing

Negotiating or mitigating penalties

Depending on the bank and your profile, you may sometimes:

• Negotiate a partial reduction of the penalty (no guarantee, but worth asking).
• Shift the refinancing date slightly to benefit from a lower outstanding principal (and thus a lower penalite_remboursement).
• Consider an internal renegotiation with your current bank, which may carry fewer additional fees even if the penalty still applies.

Simulate several what-if scenarios

Before deciding between refinancing, keeping your current mortgage, selling, or renting, test multiple hypotheses in a buy or rent simulator:

• Immediate refinancing with today’s penalite_remboursement.
• Refinancing in 2–3 years, with lower outstanding principal (hence lower penalty, but uncertain future rates).
• Sell-and-rent scenario, including penalties and transaction costs (notary, agency).

You’ll see how the total cost of ownership compares with the total cost of renting when you factor in investment returns, inflation, rising rents, property tax, and of course early repayment penalties.

Conclusion: penalties are key, but not the only variable

Early repayment penalties are a central piece of any refinancing decision and, more broadly, of your overall buy or rent strategy. Misjudged, they can turn an apparently attractive refinancing into a neutral or negative deal. Properly integrated into your simulation via the penalite_remboursement parameter, they give you a realistic picture of your true mortgage cost.

The decision to refinance or not, to remain a homeowner or to rent, will always depend on your personal situation (life plans, holding period, savings capacity, risk tolerance). For that reason, this text is not personalised financial advice.

To ground your decision in concrete numbers and compare, side by side, different buy or rent scenarios with or without refinancing—accurately including early repayment penalties—simulate your situation on buy-or-rent.net.