DSN 2027 calendar: filing deadlines on the 5th and the 15th, month by month

Quick answer. In 2027, the DSN (the monthly social security return) is still due on the 5th of the following month for employers with at least 50 employees who run payroll within the month worked, and on the 15th in the other cases. Six deadlines fall on a weekend or a public holiday and move to the next working day, including the deadline for April payroll: Saturday 15 May comes just before Whit Monday, so the deadline is Tuesday 18 May 2027.

This page sets out the 2027 calendar and what it changes in the way payroll is organised. The dates are calculated from the two articles of the French Social Security Code that set the deadlines (R. 243-6 and R. 133-14) and from the list of public holidays in 2027. How the return works, its data blocks and the 2026 deadlines are still covered in our 2026 DSN guide.

The year's deadlines run from Tuesday 5 January 2027, for December 2026 payroll, to Monday 17 January 2028, for December 2027 payroll. For each period of employment, the table gives the deadline on the 5th and the deadline on the 15th; dates in bold have already been moved because the original day is a Saturday, a Sunday or a public holiday.

The deadline on the 5th applies to employers with at least 50 employees whose payroll is run during the month worked. The deadline on the 15th applies to all other employers.

How these dates are calculated#

Article R. 243-6 of the Social Security Code sets the payment of contributions on the 5th or the 15th of the month following the period of work, and Article R. 133-14 aligns the DSN with those same dates. The second article adds that a time limit expiring on a public holiday or a non-working day is extended to the next working day.

The official calendar of net-entreprises.fr applies this extension. For October 2026 payroll, it sets the deadline on the 15th to Monday 16 November, the 15th being a Sunday; for November 2026 payroll, it sets the deadline on the 5th to Monday 7 December, the 5th being a Saturday. The 2027 dates follow the same logic. As at 22 October 2026, net-entreprises.fr had published its calendar only for November and December 2026: the 2027 dates given here are calculated on Articles R. 243-6 and R. 133-14 and remain to be checked against its calendar once it is published.

The underlying rule does not move. What changes in 2027 is mainly the calendar and the January technical standard; penalties keep their percentages for now.

Six deadlines in the calendar fall on a Saturday, a Sunday or a public holiday. Each one moves to the first working day that follows:

• April payroll, deadline on the 15th: Saturday 15 May, then Sunday 16 and Whit Monday 17, hence Tuesday 18 May 2027.
• May payroll, deadline on the 5th: Saturday 5 June, hence Monday 7 June.
• July payroll, deadline on the 15th: Sunday 15 August, Assumption Day, hence Monday 16 August.
• August payroll, deadline on the 5th: Sunday 5 September, hence Monday 6 September.
• November payroll, deadline on the 5th: Sunday 5 December, hence Monday 6 December.
• December 2027 payroll, deadline on the 15th: Saturday 15 January 2028, hence Monday 17 January 2028.

Why Tuesday 18 May and not Monday 17 May#

Whit Monday is one of the statutory public holidays listed in Article L. 3133-1 of the French Labour Code: it is a public holiday, including in a business that uses it as its solidarity day (journée de solidarité). The deadline of Saturday 15 May therefore passes over Sunday 16 and Monday 17 and lands on Tuesday 18 May 2027.

Treating Monday 17 May as the deadline by mistake costs nothing: filing on the 17th simply means filing early. According to net-entreprises.fr, a "cancel and replace" DSN is only accepted until midnight on the day before the deadline; for a deadline on Tuesday 18 May, that day before is Whit Monday.

Our view. May 2027 has two public holidays on weekdays, Ascension Day on Thursday 6 May and Whit Monday on Monday 17 May. We recommend filing the DSN for April payroll by Friday 14 May at the latest: the question of the 17th or the 18th then no longer matters, and a correction is still possible before the deadline. The same reflex applies in summer: the DSN for July payroll, moved to Monday 16 August, should be prepared before staff leave on holiday.

Public holidays and working days for the year are set out month by month in our article on working days in 2027.

Alsace-Moselle: the same calendar#

The two public holidays specific to the local law of Alsace-Moselle, Good Friday (Friday 26 March 2027, in the municipalities concerned) and 26 December 2027, a Sunday, fall neither on a 5th nor on a 15th. DSN deadlines are therefore the same as elsewhere in mainland France.

The deadline on the 5th requires two conditions together: a headcount of at least 50 employees and payroll run during the same month as the period of work. If either one is missing, the deadline is the 15th. A business with 80 employees whose January payroll is run on 3 February is therefore on the 15th, whereas a business with 60 employees that runs its January payroll on 28 January is on the 5th.

The DSN is filed every month for each establishment, identified by its SIRET number, using the payroll data of all employees. A business with several establishments therefore keeps track of one monthly return per establishment.

In this last case, the DSN remains due every month, even if no wages have been paid, as long as the employer has not asked its collection body to close its account or obtained permission to stop filing because it no longer employs staff (Article R. 133-14).

An employer with fewer than eleven employees may, subject to the exceptions set out in the text, pay its contributions every quarter, within the first fifteen days of the following calendar quarter (Article R. 243-6-1 of the Social Security Code). The DSN remains monthly and due on the 15th. In 2027, quarterly payments fall on Friday 15 January (fourth quarter of 2026), Thursday 15 April, Thursday 15 July and Friday 15 October.

The option is requested in writing from the collection body before 31 December, or when the first employee is hired. Unless it is renounced by 31 December at the latest, it is renewed for the following year. For 2027, an employer that already has employees therefore sends its request before 31 December 2026, and one that wishes to renounce the option does so by that date at the latest; an employer that hires its first employee in 2027 can opt at that point.

Trade-off: pay every month or every quarter? Quarterly payment keeps cash in the business for longer, but concentrates three months of contributions on a single date. A payment incident on that day can trigger the 5% surcharge (unless the right to make a mistake applies, Article R. 243-11) on an amount that covers a whole quarter. The option makes sense when receipts are regular and predictable; a business whose cash position swings sharply from one month to the next may prefer to keep smaller monthly payments. In both cases, the monthly DSN remains due on the 15th.

As a general rule, an event that must be reported is declared at the latest with the DSN for the month in which it occurs. Some events have a shorter time limit, set by ministerial order and which cannot exceed five working days: the end of the employment contract and, where the employer is not subrogated to the employee's right to daily benefits, the start and end of a leave of absence (illness, workplace accident or occupational disease, maternity, paternity and childcare leave, adoption, additional birth leave). The text provides for exceptions (Article R. 133-14, II).

For an employer on the 15th, this short time limit can bring the monthly DSN itself forward. Where the event occurs between the first day of the month and the day before the 15th, and its reporting time limit expires before the 15th, the DSN for the previous month's pay must be filed within that same time limit (Article R. 133-14, I).

Illustrative example. A business with 20 employees, on the 15th deadline, sees an employee who has resigned leave on Monday 3 May 2027, at the end of the notice period. The end-of-contract report must be sent within no more than five working days, a time limit that expires well before 15 May. The DSN for April payroll therefore cannot wait until Tuesday 18 May: it goes out within the same time limit as the report.

Additional birth leave became one of the DSN events with Decree no. 2026-425 of 30 May 2026, in force on 1 July 2026 (Articles R. 133-13 and R. 133-14). According to net-entreprises.fr (news item of 30 September 2026, amended on 6 October 2026), it has been declared since October 2026 through a DSN event report, within 5 days of the start of the leave; at the date of that news item, the operator also requires the French health insurance fund's form. How event reports work is explained in our article on event-based DSN for a leave of absence or the end of a contract.

The Social Security Code sets a day, not a time. The time comes from the operator: according to the DSN page of net-entreprises.fr, the return is filed before noon on the deadline day, the 5th or the 15th of the following month, and the "cancel and replace" mode is only accepted until midnight on the day before.

In practice, the last useful moment is therefore not the deadline day but the evening before, if you want to keep the option of replacing a faulty file. The checks to run before sending are set out in our article on making the monthly DSN reliable before filing, and where they sit in the month in our article on the monthly payroll cycle.

Penalties are expressed as a percentage of the monthly social security ceiling (PMSS) or of the contributions due, and no text published as at 22 October 2026 amends these percentages. The euro amounts follow the 2027 PMSS, to be set by a ministerial order that had not been published by that date.

As a general rule, the provisional assessment is notified within one month of the filing deadline.

Three worked examples#

Illustrative example 1: three days late count as a whole month. A business with 30 employees, on the 15th deadline, files the DSN for September payroll on Monday 18 October 2027 instead of Friday 15 October. The delay is a part of a month: the penalty is 30 times 1.5% of the PMSS. The cap of 150% of the PMSS does not come into play, as the total stays below it.

Illustrative example 2: the cap only works once a year. A business with 120 employees, on the 5th deadline, files the DSN for May payroll on Wednesday 9 June 2027 instead of Monday 7 June. The calculation gives 120 times 1.5% of the PMSS, which is more than the cap of 150% of the PMSS. The delay does not exceed five days and it is the first one in the calendar year: the penalty is brought down to 150% of the PMSS. The same delay in November would no longer benefit from the cap: the penalty would remain 120 times 1.5% of the PMSS.

Illustrative example 3: late payment and the right to make a mistake. A business pays €20,000 of contributions ten days late. Surcharges: 5% of €20,000, i.e. €1,000, plus 0.2% for a part of a month, i.e. €40, making €1,040 in total. These surcharges are not due if the business meets its DSN obligations, pays within thirty days (or signs within that period a payment plan that it then complies with), has had no late payment in the previous twenty-four months, and if their amount remains below the monthly value of the social security ceiling (Article R. 243-11).

The new classification of economic activities, NAF 2025, comes into force on 1 January 2027 (Decree no. 2025-736 of 31 July 2025). According to net-entreprises.fr, the P27V01 DSN standard therefore removes the "APEN code" and "APET code" fields: the NAF code no longer has to be entered in the DSN, except for a workplace that has no SIRET number, where it is entered using the NAF 2025 codes. Still according to the operator, NAF 2025 is expected to apply from the January 2027 DSN go-live, whether the software publisher uses the P26 or the P27 standard.

According to the maintenance log published by net-entreprises.fr (version of the week of 14 September 2026), technical specifications 2027.1.1, published on 10 June 2026, and that log will make up the standard in operation in January 2027. The log also sets out the rules for splitting the monthly DSN into fractions.

In practice. Ask your payroll software publisher, or the provider that produces your DSN returns, on what date version P27V01 will be installed. Before the first payroll of 2027, identify any workplaces without a SIRET number: they are the only ones for which a NAF code still has to be entered.

• Deadline on the 5th or the 15th checked against headcount and payroll date
• The six moved dates entered in the payroll schedule, including Tuesday 18 May 2027
• DSN for April payroll planned for Friday 14 May 2027 at the latest
• P27V01 standard version confirmed by the software publisher before January 2027 payroll
• Workplaces without a SIRET number identified, with their NAF 2025 code
• Option for quarterly payment (fewer than 11 employees) requested in writing before 31 December 2026, or when the first employee is hired in 2027; renunciation by 31 December 2026 at the latest
• Process for end-of-contract and absence reports set to no more than five working days
• Additional birth leave included in the DSN event report process
• Account with no employees: closure or permission requested, failing which the DSN remains due every month

This article presents the texts in force and the dates that follow from them; the deadline that applies to your business should be checked against your situation and the net-entreprises.fr calendar. To organise payroll and returns around this calendar, you can see our payroll and HR page or contact our chartered accounting firm in Paris 8th.