Proving Employment Tenure under New Regulations – Challenges and Implications for Employees and Employers

New rules for recognising periods of professional activity

Beginning 1 January 2026, a significant amendment to the Labour Code came into force, expanding the range of periods that may be counted toward employment tenure. In addition to traditional employment relationships, various other forms of professional activity—such as services performed under civil law contracts or self‑employment—may also be included. In practice, this means that employment tenure, which determines access to numerous employee rights, will become a broader and more complex concept.

Where a given activity was covered by social or health insurance, the period may be confirmed through certificates issued by the Social Insurance Institution. These documents are intended to verify both the fact of performing work and the duration of that activity.

Evidentiary difficulties with service contracts and pre‑1999 periods

The greatest challenges will arise in situations where work was performed under service contracts during periods not subject to mandatory insurance. This applies in particular to pupils and students under the age of 26, who are exempt from social insurance when performing work under a service contract. In such cases, the Social Insurance Institution holds no records, and the burden of proof rests entirely on the individual.

A similar issue concerns periods prior to 1999, when individual insurance accounts did not yet exist. Demonstrating the performance of a service contract from more than two decades ago may be especially difficult due to the passage of time, missing documentation, or the dissolution of the former contracting entity.

In practice, an individual may rely on the contract itself, payment confirmations, receipts, or a written statement from the former principal. However, the employer is not obliged to accept every document as credible, and the assessment of evidence remains within the employer’s discretion.

Foreign work activity – lack of clear guidelines

The amendment also covers periods of work performed abroad under forms other than an employment relationship. The legislation does not specify which documents should confirm such periods. The explanatory notes suggest a broad range of acceptable evidence, including tax documents, confirmations from foreign insurance institutions, or certificates issued by foreign employers.

The absence of precise rules may lead to disputes, particularly because employers may require sworn translations, and the diversity of employment forms in other jurisdictions complicates the assessment of their legal nature.

Financial and organisational consequences for employers

Recognising additional periods of professional activity as employment tenure may have significant financial implications, especially for public sector entities. A longer tenure may accelerate entitlement to 26 days of annual leave, increase seniority‑based allowances, or lead to earlier eligibility for jubilee awards.

Employees in the public sector will have 24 months to document additional periods predating 1 January 2026. If they succeed, employers will be required to recalculate allowances and pay retroactive adjustments. This may also affect benefits such as maternity allowances or rehabilitation benefits.

In the private sector, the impact will depend on internal regulations, as the law does not impose an obligation to grant seniority allowances or jubilee awards.

Risk of disputes and the role of labour courts

If an employer refuses to recognise the documents presented, the employee may pursue the matter in court. Labour court proceedings allow for the use of a full range of evidence, including witness testimony and the employee’s own statements. Courts also have greater discretion in assessing the credibility of documents than employers.

It is likely that the number of disputes concerning the determination of employment tenure will increase, particularly in the public sector, where employers must exercise heightened caution due to the responsibility for proper use of public funds.

Summary

The new regulations on determining employment tenure introduce significant changes for both employees and employers. While expanding the catalogue of periods counted toward tenure strengthens employee protection, it also creates numerous evidentiary and organisational challenges. The lack of clear guidelines for documenting certain forms of professional activity may lead to disputes, with many cases ultimately resolved by labour courts. It is advisable to prepare internal procedures now to ensure efficient and reliable verification of submitted documents and to minimise the risk of errors and misunderstandings.

attorney at law Marta Strzecha-Bociąga

legal assistant Julia Sośniak