Part-time employees’ claims for back pay of overtime premiums are subject to a five-year limitation period

Part-time employees’ claims for back pay of overtime premiums are subject to a five-year limitation period

On 4 September 2026, an industrial arbitration tribunal held that part-time employees’ claims for back pay of overtime premiums are subject to a five-year limitation period. The tribunal also held that limitation periods may be interrupted as early as upon a request for industrial relations proceedings. 

The case arose from two arbitral awards of 4 February 2026 (FV2025.528 and FV2025.795), which held that certain specified collective agreement provisions on overtime pay in the industrial collective agreements and in collective agreements in the public sector (municipalities, regions and the state) were incompatible with the EU Part-Time Work Directive, including the principle of non-discrimination, insofar as those provisions entitled part-time employees to overtime pay only for hours worked in excess of the normal working hours applicable to full-time employees.

The awards also held that part-time employees could be entitled to back pay of overtime premiums. However, they did not determine the issue of limitation.

The arbitration tribunal addressed that issue in this case.

Background: A part-time cleaning assistant claimed back pay of overtime premiums

Since 1 January 2016, A had been employed by B as a part-time cleaning assistant. A’s employment was governed by the service collective agreement for the private sector, and during his employment, A had performed work in excess of the working hours stipulated in his employment contract and had received his ordinary pay, but no overtime premiums, for that work.

On 9 January 2026, and before the issuance of the two industrial arbitration awards of 4 February 2026 (FV2025.528 and FV2025.795), A’s union contacted B regarding the underpayment of wages to A and requested local negotiations concerning A’s wage claim.

The local negotiations took place on 3 February 2026, and the parties agreed to put the matter on hold pending the collective bargaining parties’ discussion of the pending part-time cases.

Following the two industrial arbitration awards of 4 February 2026 determining the part-time cases, A’s union claimed back pay of overtime premiums to A for all work performed in excess of A’s contractually agreed working hours from 1 January 2016, that is, for the entire period of employment.

On 14 April 2026, A’s union requested that the matter be referred to industrial arbitration. In the arbitration proceedings, A’s union claimed back pay of overtime premiums to A for all work performed in excess of A’s contractually agreed working hours from 1 January 2016, that is, for the entire period of employment.

The tribunal was solely required to determine the limitation issue

At the initial stage, the arbitration tribunal was solely required to determine whether part of A’s claim for back pay was time-barred. 

Five-year limitation period for claims for back pay

The presiding arbitrator held that A’s potential claim for back pay of overtime premiums was subject to the five-year limitation period laid down in section 4(1) of the Danish Limitation Act. 

The presiding arbitrator further held, pursuant to section 2(1) of the Danish Limitation Act, that the limitation period began to run at the time when payment of the overtime premium could have been claimed.

Was the limitation period suspended?

The parties disagreed as to whether the five-year limitation period had been suspended pursuant to section 3(2) of the Danish Limitation Act, with the result that A could claim back pay for the past 10 years, pursuant to section 4(2), in conjunction with section 3(3), paragraph (4) of the Danish Limitation Act. Under those provisions, a claim becomes time-barred no later than 10 years after the commencement date under section 2. 

The claimant submitted that the limitation period had been suspended due to excusable ignorance of the claim under section 3(2) of the Danish Limitation Act. The claimant argued that the matter concerned the interpretation of the collective agreement and that, accordingly, the limitation period had been suspended from the commencement of employment in 2016 until the issuance of the arbitral awards of 4 February 2026.

The respondent submitted that A had not been excusably ignorant of the claim. The respondent contended that the issue was not ignorance of the rules laid down in the collective agreement, but rather ignorance of EU law, including the proper general interpretation of the principle of non-discrimination under the EU Part-Time Work Directive. A had therefore been acting under a mistake of law, which did not justify suspension of the limitation period.

The presiding arbitrator initially observed that, pursuant to case law, ignorance of the terms of a collective agreement may justify suspension of the limitation period pursuant to section 3(2) of the Danish Limitation Act.

The presiding arbitrator then stated that A’s potential claim for back pay was not based on ignorance of the provisions of the service collective agreement, but rather on A’s lack of awareness of the implications of the principle of non-discrimination under the EU Part-Time Work Directive in relation to remuneration for overtime work performed by part-time employees.

On that basis, the presiding arbitrator found that A had been acting under a mistake of law.

The presiding arbitrator further stated that a mistake of law does not normally justify suspension under section 3(2) of the Danish Limitation Act, and that case law requires special circumstances to warrant a departure from this general rule. 

The presiding arbitrator found that the fact that a provision in a Danish collective agreement implementing an EU obligation was found to be incompatible with EU law did not, in itself, constitute a special circumstance warranting suspension.

As no other special circumstances existed, the presiding arbitrator found no basis for exceptionally suspending the limitation period on grounds of mistake of law.

A’s claim for back pay was therefore subject to the five-year limitation period. Consequently, A could not claim overtime premiums going back 10 years.

When was the limitation period interrupted?

The parties disagreed as to when the limitation period applicable to the claim for back pay was interrupted.

The claimant submitted that, pursuant to section 21(5) of the Danish Limitation Act, the limitation period was interrupted as early as 9 January 2026, when the union’s local branch requested local negotiations regarding A’s wage claim.

The respondent submitted that, pursuant to section 16(3) of the Danish Limitation Act, the limitation period was not interrupted until, at the earliest, 14 April 2026, when industrial arbitration was requested.

With reference to the explanatory notes to section 21(5) of the Danish Limitation Act and the special nature of industrial relations proceedings, the presiding arbitrator held that the initiation of industrial relations proceedings has an interrupting effect pursuant to section 21(5).

The presiding arbitrator stated that it could not have been the intention of the Danish Limitation Act to prevent a person, who is legally barred under a collective agreement from requesting industrial arbitration, from interrupting the limitation period by taking the procedural steps required to subsequently initiate industrial arbitration. In the presiding arbitrator’s view, substantive considerations therefore supported the conclusion that the limitation period is interrupted when industrial relations proceedings are initiated in accordance with the requirements imposed by the applicable collective agreement. 

The presiding arbitrator further stated that this applies irrespective of the type of industrial relations meeting that must be convened under the collective agreement. 

On that basis, the presiding arbitrator held that the request for local negotiations on 9 January 2026 interrupted the limitation period pursuant to section 21(5) of the Danish Limitation Act.

Did a procedural agreement suspend the limitation period before 9 January 2026?

The parties also disagreed as to whether the limitation period had been suspended before 9 January 2026, on grounds other than those set out in section 3(2).

The claimant submitted that the limitation period must have been suspended by a collective agreement protocol entitled “Procedural agreement concerning part-time work,” concluded by the collective agreement parties on 27 February 2025 in connection with the 2025 collective agreement. The protocol stated that the collective agreement parties had agreed to await the outcome of the industrial arbitration proceedings to be commenced in relation to the industry collective agreements. They had further agreed that no cases concerning overtime pay for part-time employees within the scope of the service collective agreement could be brought until the decision was issued.

Accordingly, until the decision in the industrial sector had been issued, the parties were barred under the protocol from bringing cases concerning overtime pay for part-time employees within the scope of the service collective agreement.

The presiding arbitrator found that, although the protocol did not expressly address limitation, it must be understood to mean that, for limitation purposes, cases falling within the scope of the service collective agreement were stayed (suspended) until the test case in the private sector had been decided. That decision was issued on 4 February 2026.

The presiding arbitrator consequently found that the part of A’s claim for back pay of overtime premiums that had fallen due before 27 February 2020 was time-barred.

Three-year limitation period for interest claims

The presiding arbitrator held that, since interest on employment law claims is subject to a three-year limitation period pursuant to section 3(1) of the Danish Limitation Act, A’s claim for interest falling due before 27 February 2022 was time-barred.

Our comments

The award is relevant to all private sector employers that employ, or have employed, part-time employees and may face claims for back pay of overtime premiums following the arbitration awards of 4 February 2026 (FV2025.528 and FV2025.795).

The award establishes that claims for back pay of overtime premiums are subject to a five-year limitation period, and that interest claims are subject to a three-year limitation period.

The same must also apply to public-sector employers. 

The award further establishes that, pursuant to section 21(5) of the Danish Limitation Act, the limitation period may be considered interrupted as early as the point at which the industrial relations proceedings required under the collective agreement framework are initiated, and that a request for local negotiations may be considered to have the effect of interrupting the limitation period under that provision.

The award also shows that employers should be mindful that protocols and procedural agreements may have implications for limitation periods, even where limitation is not expressly addressed in those documents.

At Poul Schmith, we advise employers in both the private and public sectors on employment law issues that may arise in connection with part-time employees’ claims for back pay of overtime premiums, including limitation periods, suspension and procedural agreements.

Contact our specialists if you need advice on the applicable limitation periods for part-time employees’ claims for back pay.

This news item is based on an industrial arbitration award dated 4 September 2026 in case no. FV2026.573.