Late payment penalties are one of the most important protective mechanisms in commercial law. Yet many businesses never apply them, allowing clients to delay payments with no financial consequence. In France, for H1 2026, the applicable rate is 12.15% per annum, and a flat-rate compensation of €40 is automatically due for each overdue invoice. Understanding the exact calculation, legal obligations, and mandatory mentions in your T&Cs is essential to protect your cash flow and comply with the Commercial Code.
Definition of late payment penalties
Simple definition
Late payment penalties are interest automatically owed by a debtor who has not settled an invoice before the agreed due date. They constitute financial compensation for the creditor, who bears a cash flow loss for the duration of the delay.
Contrary to common belief, late payment penalties do not require any prior action from the creditor to be owed. They arise automatically from the first day following the due date, as a matter of right and without any prior formal demand.
In practice, two components coexist:
- The late payment penalties themselves: interest calculated on the total invoice amount (including VAT), at the applicable legal rate
- The €40 flat-rate compensation: a fixed amount owed for collection costs, in addition to the penalties
Legal framework
Late payment penalties are governed primarily by:
- Article L441-10 of the Commercial Code: the creditor’s obligation to include the penalty rate in their T&Cs, and the right to penalties without a formal demand
- Article L441-9 of the Commercial Code: the obligation to mention the penalty rate on each invoice
- Article D441-5 of the Commercial Code: the flat-rate compensation amount set at €40
- LME Law no. 2008-776 of 4 August 2008: the founding legislation, reinforced by the Macron Law 2015 and the PACTE Law 2019
These provisions apply to all commercial transactions between businesses, with no exception based on size or sector. For more on the general legal framework, see our article on the LME Law.
How to calculate late payment penalties
The applicable rate: ECB + 10 points (or legal floor)
The late payment penalty rate is defined in Article L441-10 of the Commercial Code. It corresponds to the higher of:
- The ECB refinancing rate plus 10 percentage points
- 3 times the legal interest rate (statutory minimum floor)
For H1 2026 (rates in force since 1 January 2026):
| Reference | Base rate | Penalty rate |
|---|---|---|
| ECB (refinancing operations) | 2.15% | 12.15% (ECB + 10 pts) |
| Professional legal interest | 2.62% | 7.86% (3 × legal rate) |
The applicable rate for H1 2026 is therefore 12.15% per annum, as the ECB rate + 10 points is higher than the floor of 3 times the legal rate.
The ECB rate is updated twice a year: on 1 January (for the first half) and 1 July (for the second half). It is advisable to check the rate in force at each six-monthly renewal.
The calculation formula
The formula for calculating late payment penalties is:
Penalties = Total amount (incl. VAT) × Annual rate × (Number of days overdue / 365)
Detail of each variable:
- Total amount (incl. VAT): the total amount including all taxes shown on the invoice
- Annual rate: the applicable legal rate (12.15% for H1 2026, i.e. 0.1215 as a decimal)
- Number of days overdue: the number of calendar days elapsed between the due date and the actual payment date (or the calculation date if the invoice is still unpaid)
Worked example
Take an SME that issued an invoice for €10,000 (incl. VAT) due on 15 March 2026. The client pays on 15 May 2026, i.e. 61 days overdue.
Penalty calculation: 10,000 × 12.15% × (61 / 365) = 10,000 × 0.1215 × 0.1671 = €203.05
Flat-rate compensation: €40.00
Total owed in addition to the principal: 10,000 + 203.05 + 40 = €10,243.05
On a €10,000 invoice, two months of delay therefore generates over €243 in additional charges. If the business has 50 invoices overdue by a similar amount per year, that is over €12,000 in theoretical losses from not claiming its penalties.
Impact on your business
Practical consequences
Failing to apply late payment penalties has direct consequences on your cash flow and on client behaviour:
On cash flow: Every day of delay represents free credit granted to your client. In 2024, the Banque de France estimated that French SMEs would have benefited from an additional €15 billion if statutory deadlines were respected. By not claiming your penalties, you are subsidising your debtors’ working capital requirements.
On client behaviour: A client who knows they will never be penalised for late payment has no incentive to pay on time. Conversely, explicitly mentioning penalties in your T&Cs and on your invoices acts as a deterrent that encourages respect for deadlines.
On your provisions: Unclaimed penalties are theoretical receivables that do not appear in your accounts. By claiming them systematically, you improve your results and the accuracy of your accounting.
Mistakes to avoid
Mistake 1: Not mentioning the rate in T&Cs and on invoices This is an offence under the Commercial Code and makes it harder to recover penalties in case of dispute. The mention is mandatory and cannot be omitted.
Mistake 2: Applying a rate below the legal minimum Some businesses set a penalty rate in their T&Cs (for example 1.5% per month) without realising it may be below the legal minimum. The contractual rate must be at least equal to the legal minimum rate. If the contractual rate is lower, the legal rate applies automatically.
Mistake 3: Forgetting the €40 flat-rate compensation The €40 compensation is often overlooked, yet it is automatically payable on each overdue invoice. Over a large volume of invoices, the cumulative amounts can be significant.
Mistake 4: Confusing invoice date and due date Penalties run from the due date, not from the invoice issuance date. If an invoice dated 1 March has a due date of 30 March, penalties begin on 31 March, not 2 March.
Mistake 5: Waiving penalties to preserve the commercial relationship It is possible to waive penalties for a good client after an exceptional delay, but not having them in your T&Cs in the first place is a structural mistake. Having penalties in your T&Cs and choosing not to apply them in certain cases is very different from not providing for them at all.
Tools for managing late payment penalties
How to automate calculation and recovery
Manually calculating penalties for each overdue invoice is tedious and error-prone. With a significant volume of receivables, manual management quickly becomes impossible.
Modern collection tools enable you to automate:
- Detection of overdue invoices from the first day
- Automatic calculation of penalties at the applicable legal rate
- Inclusion of penalties and the flat-rate compensation in payment reminders
- Six-monthly updates to the ECB rate without manual intervention
Billabex is the AI-powered collection solution designed for B2B businesses. It automatically calculates late payment penalties on each unpaid invoice, integrates the €40 compensation, and sends your clients professional reminders detailing the amounts due.
Result: you no longer leave any penalty unclaimed, your legal compliance is assured, and your DSO decreases mechanically. Discover Billabex →
To complete your reading: the LME Law sets the legal framework for these penalties, our guide on the statute of limitations for invoices explains within what time frame you can claim them, and our complete guide on DSO shows how late payments affect your cash flow.
