Multi-agreement payroll: managing several IDCC and establishments

Quick answer. The applicable collective agreement depends on the real main activity of the company or establishment, not on the APE code. Each agreement carries an IDCC code. A business with several establishments carrying out distinct and autonomous activities may fall under several agreements, in principle one per establishment. The agreement appears on the payslip and the IDCC is reported in the DSN, for each employee.

A growing business rarely ends up doing a single job on a single site. A group opens a workshop then a retail outlet, a holding company employs support functions alongside an operating subsidiary, an SME absorbs a related activity. Each time, the same question arises when running payroll: which collective agreement applies, and should several apply? The answer is far from trivial, because the agreement sets the minimum wages, the classifications, the bonuses, the working time and the welfare cover.

This article is aimed at directors, HR managers and finance leaders of businesses with multiple activities or multiple establishments who want to secure the determination of the applicable agreement, avoid IDCC errors and make payroll and the DSN reliable. We stay here on the method: we cite no IDCC number and no figured wage scale, because each situation is settled on a case-by-case basis.

A collective agreement is a negotiated text that supplements and adapts the Labour Code for a given branch of activity. It sets rules specific to a sector: classification scales, minimum wages, contractual bonuses, working time and organisation, leave, welfare and health insurance schemes. Each agreement is identified by an IDCC code, for Collective Agreement Identifier, which serves as the unique reference in social procedures and in the DSN.

The key point, often misunderstood, is the following: the applicable agreement is determined by the real main activity of the company or establishment, not by the APE code. The APE code, assigned by INSEE, is only a statistical indicator. It may form a presumption in case of doubt, but it has no binding value in setting the agreement. It is the activity actually carried out that prevails.

Our take#

In payroll files, confusing the APE code with the collective agreement is one of the most frequent errors at the outset. A director chooses an APE code at incorporation, sometimes loosely, then mechanically applies the agreement that seems to match. If the real activity differs, the agreement applied is fragile from the very first payslip. We recommend separating the two lines of reasoning: the APE code belongs to the declaration of activity, the agreement belongs to the analysis of the real activity. On the code, see our article on the APE or NAF code at incorporation.

The determination follows a logic that is simple to state, trickier to apply. You start from the real activity, identify the main activity where there are several, then attach the corresponding branch agreement. The table below sums up the criteria and their weight.

Where a single establishment carries out several activities, the main activity determines the single agreement applicable to all the employees of the site. The main activity is assessed in light of turnover and, depending on the case, the dominant headcount. There is no universal rule: the analysis is carried out text in hand, comparing the real activity with the scope of each candidate agreement.

Yes, in a specific situation. A business with several establishments carrying out clearly different and autonomous activities may fall under several collective agreements, in principle one agreement per establishment with a distinct activity. The logic is clear: each autonomous establishment is subject to the agreement of its own real activity. Conversely, on a single establishment combining several activities, the rule is the opposite: a single agreement applies to all employees, that of the site's main activity.

The autonomy criterion is central. A secondary establishment that merely extends the head office's activity, with no organisation or activity of its own, does not justify a separate agreement. Conversely, a site with its own activity, its own resources and genuine autonomy may fall under a different agreement. The boundary is factual and must be documented.

The underestimated risk#

The most frequently overlooked risk is not the absence of an agreement, but the default attachment, never re-examined after the business evolves. A company opens a second establishment with a different activity and keeps, out of habit, applying the historical agreement to all its employees. As long as nobody challenges it, nothing shows. The day an employee, an inspection or a dispute compares the payslip with the minimums of the right agreement, the gap becomes a wage catch-up, potentially over several years. The attachment must therefore be checked at each change of activity or structure, not only at incorporation.

The choice of agreement is not an administrative formality: it runs through the whole of payroll. Each agreement imposes its own rules, which translate directly onto the payslip and into the declarations.

• Classifications and scales: the agreement sets the coefficients and the contractual minimum wages, which bind the employment contract.
• Contractual bonuses: seniority bonus, thirteenth month or other benefits provided by the branch text.
• Working time and organisation: arrangements specific to the agreement, which may differ from ordinary law.
• Leave and absences: contractual rules sometimes more favourable than the law.
• Welfare and health insurance: mandatory branch schemes, with their cover and their rates.

Two reporting obligations frame this choice. First, the payslip must state the collective agreement applicable to the employee. Second, the DSN carries the IDCC for each employee and each contract. In a multi-agreement business, this means employees of the same employer may legitimately show different IDCC depending on their establishment of attachment. Payroll must therefore be configured establishment by establishment, and the DSN must faithfully reflect that configuration. To make this declaration reliable, see our article on making the monthly DSN reliable, and on payslip mentions, our note on the new 2026 payslip.

Here is a structured approach to set and document the applicable agreement, establishment by establishment.

1. Describe the real activity of each establishment, independently of the APE code, starting from what is actually produced or sold on each site.
2. Identify the main activity where an establishment carries out several activities, in light of turnover and dominant headcount.
3. Compare the real activity with the scope of the candidate agreements, text in hand, to retain the agreement whose perimeter genuinely covers the activity.
4. Assess the autonomy of each establishment to determine whether it justifies its own agreement or attaches to that of the head office.
5. Formalise and document the chosen attachment for each establishment, with the analytical elements that founded it.
6. Configure payroll and the DSN accordingly, with the right IDCC for each employee and each contract.
7. Re-examine the attachment at each change of activity, organisation or group structure.

This checklist helps verify that nothing is left to habit:

• The real activity of each establishment is described and dated.
• The main activity is justified by figures where there are several.
• The scope of the chosen agreement has been checked in the text.
• Each payslip states the right agreement.
• Each IDCC in the DSN matches the establishment of attachment.
• The file keeps a written record of the analysis.

Take a situation we regularly come across, presented anonymously. A company runs two establishments with distinct trades: a manufacturing site on one side, a site dedicated to trading and distribution on the other, each with its own teams, resources and organisation. For convenience, payroll long applied a single agreement to all employees.

The analysis, carried out text in hand, shows that the two establishments are autonomous and carry out activities falling under different branches. Attaching everything to a single agreement does not reflect that reality. The work then consists of attaching each establishment to the agreement of its real activity, checking that the corresponding minimums and bonuses are properly applied, then correcting the payroll configuration and the IDCC reported in the DSN for each population. No figure is invented here: the stake is the attachment method, not a scale.

What the administration looks at#

In the event of an inspection, attention focuses first on the consistency between the real activity, the agreement applied and the IDCC declared. An IDCC that is wrong or missing in the DSN, an agreement stated on the payslip with no connection to the activity, or contractual minimums not respected are all warning signs. The attachment is therefore better documented: an analysis note attaching each establishment to its agreement, on the basis of the real activity, is worth more than an implicit choice never justified.

• Never infer the agreement from the APE code alone: it is a statistical indicator, not a binding rule.
• On a single establishment, do not apply several agreements depending on the employees: a single agreement, that of the main activity, applies to the whole site.
• Re-examine the attachment at each establishment opening, activity acquisition or reorganisation: the initial choice does not hold indefinitely.
• Check the consistency between the payslip agreement and the DSN IDCC for each employee: a mismatch is a warning sign.
• Keep a written record of the analysis: in case of dispute or inspection, the documented file makes the difference.