Posted workers from Sweden to Poland – A1

A Swedish technology company wins a six-month infrastructure contract in Warsaw. The project manager calls HR the same afternoon: "When can our engineers start on site?" The honest answer is more complicated than the question suggests. Before a single Swedish employee sets foot in Poland under a Swedish employment contract, the employer must hold a valid A1 certificate confirming that the worker remains subject to Swedish social security – not Polish. Without it, both the Swedish sending company and the Polish host entity face retroactive contribution assessments, fines, and reputational damage that cannot easily be undone.

An A1 certificate is an official document issued by the Swedish Social Insurance Agency (Försäkringskassan) confirming that a posted worker continues to pay social contributions in Sweden during a temporary assignment in Poland. Under EU Regulation 883/2004 on the coordination of social security systems, a worker may remain in the home-country social security scheme for up to 24 months. The certificate must be obtained before the posting begins – retroactive applications are possible but carry compliance risk and may not be accepted by Polish authorities.

This guide walks through the full A1 procedure for Swedish employers posting workers to Poland: the legal framework, step-by-step application process, timelines, costs, common errors, and three business scenarios that illustrate where the process can go wrong. It also explains how the A1 obligation intersects with Polish labour law requirements that apply the moment a worker crosses the border.

What legal framework governs Swedish postings to Poland?

The starting point is EU Regulation 883/2004, which coordinates social security across member states. Both Sweden and Poland are EU members, so the regulation applies directly. The core rule is simple: a worker is ordinarily insured in the country where they work. Posting is the exception – it allows the home-country scheme to continue, but only if specific conditions are met and an A1 certificate is held.

For the posting exception to apply, three conditions must be satisfied. First, the worker must have been subject to Swedish social security immediately before the posting. Second, the Swedish employer must carry on substantive activity in Sweden – not merely administrative functions. Third, the posting must be temporary, with a maximum duration of 24 months under a single A1. These are not formalities. The Försäkringskassan (Swedish Social Insurance Agency) assesses each application, and Polish labour inspectors from the Państwowa Inspekcja Pracy (National Labour Inspectorate, PIP) can request to see the certificate at any time during the posting.

Polish law adds a separate layer. Under the Polish Act on Posted Workers (implementing EU Directive 2018/957), the sending employer must notify the PIP before the posting starts. The notification is made online and must include the worker's details, the Polish host entity, the nature of work, and the expected duration. Failure to notify triggers a fine of up to PLN 30,000 per worker. The A1 certificate and the PIP notification are two distinct obligations – one addresses social security, the other addresses labour law compliance.

Additionally, posted workers are entitled to Polish minimum employment conditions from day one. This covers minimum wage (PLN 4,666 gross per month in 2026), maximum working hours, health and safety rules, and equal treatment protections. Swedish employers are often surprised to learn that their generous Swedish employment terms do not automatically satisfy Polish minimum standards – the comparison must be made condition by condition.

How do you apply for an A1 certificate through Försäkringskassan?

The application is filed with Försäkringskassan in Sweden, not with any Polish authority. There is no filing fee. Processing typically takes 4 to 8 weeks, though straightforward cases are sometimes resolved in 3 weeks. Employers should apply at least 6 weeks before the posting start date to avoid a gap in certification.

The process follows five steps:

Gather supporting documents: employment contract, proof of Swedish social security registration, description of the Polish assignment, and evidence of the employer's substantive Swedish activity.
Complete the application form (FK 5456 or the online equivalent on Försäkringskassan's portal) and submit on behalf of the employee.
Receive the certificate – typically valid for the duration of the posting, up to 24 months.
Provide a copy to the Polish host entity and keep the original accessible on site.
File the PIP notification in Poland via the online portal at pip.gov.pl before work begins.

One practical point: the certificate is issued per worker, not per project. If a Swedish employer posts five engineers to Warsaw, five separate A1 certificates are required. Each application must reflect the individual worker's circumstances. A common shortcut – submitting a single group application – is not accepted by Försäkringskassan.

Extensions beyond 24 months require a separate procedure. The employer must apply for an exception agreement between Sweden and Poland under EU rules. These agreements are discretionary and take considerably longer – sometimes 3 to 6 months. Planning the project timeline around the 24-month ceiling is far more efficient than relying on an exception.

What are the most common mistakes Swedish employers make?

Starting the posting before the A1 certificate is issued is the single most frequent error. The certificate must be held before work begins – not applied for, but held. Polish labour inspectors from the PIP can conduct on-site checks and demand to see the document on the spot. If the worker cannot produce it, the inspector may treat the posting as non-compliant, triggering a formal investigation. Retroactive certification does not erase the period of non-compliance.

We secured a reversal of a retroactive social contribution assessment exceeding PLN 180,000 for a logistics client in the Mazowieckie region (autumn 2025). The employer had obtained the A1 certificate two weeks after the posting started. The gap was short, but the ZUS (Social Insurance Institution) treated the entire pre-certificate period as uninsured in Sweden. The case was resolved, but it required months of correspondence and formal proceedings.

Three further mistakes appear regularly:

Omitting the PIP notification entirely, treating the A1 certificate as the only compliance step.
Failing to apply Polish minimum wage rules, particularly where the Swedish salary is paid in SEK and the PLN equivalent fluctuates below the statutory floor.
Allowing the posting to extend beyond 24 months without either obtaining an exception agreement or transitioning the worker to a Polish employment contract.

Each of these errors carries personal liability risk for the HR manager or director who signed off on the arrangement. Under Polish employment law, the responsible individual – not just the legal entity – can be fined. That consequence is irreversible once a PIP enforcement decision is issued.

How do three business scenarios change the compliance picture?

The A1 procedure is the same in every case, but the surrounding compliance requirements shift significantly depending on the business context. Three scenarios illustrate the range.

Manufacturing. A Swedish industrial group posts a team of 12 technicians to its Polish subsidiary in Silesia for 18 months to oversee equipment installation. The A1 applications are straightforward – the workers have been on Swedish payroll for years and the Swedish parent clearly conducts substantive business. The main risk is the PIP notification: with 12 workers, any omission is immediately visible. The employer should also check whether the Polish subsidiary qualifies as a "host entity" under Polish law, which triggers additional obligations around record-keeping and document retention for 2 years after the posting ends.

IT services. A Stockholm-based software house posts two developers to a Warsaw client for 8 months. The developers work remotely from a co-working space three days a week and at the client's office two days. The hybrid arrangement does not eliminate the posting status – the workers are still performing work in Poland under a Swedish contract. The A1 must cover the full 8-month period. One detail matters here: if the workers also work from Sweden during the posting (even occasionally), the employer may need to address multi-state working rules under Regulation 883/2004, which can affect which country's social security applies.

Foreign investor. A Swedish private equity fund is setting up a Polish operating company. During the 3-month incorporation period, the fund's Swedish CFO travels to Warsaw weekly to manage the process. Even short-duration, high-frequency visits can constitute a posting if the CFO is performing work in Poland. The Försäkringskassan and the Polish Zakład Ubezpieczeń Społecznych (Social Insurance Institution, ZUS) both take the view that substance matters more than formal labels. An A1 certificate for a 3-month posting is the safer approach – and a far smaller cost than a ZUS audit.

For comparison across EU jurisdictions, our guides on posted workers from Cyprus to Poland and posted workers from Luxembourg to Poland set out how the same framework applies in different home-country contexts.

What should Swedish employers prepare before the posting starts?

A checklist approach prevents the most common gaps. The following items should be in place before the worker's first day in Poland:

A1 certificate issued by Försäkringskassan – original held by the worker, copy with the Polish host entity.
PIP notification submitted and confirmed – retain the confirmation reference number.
Polish minimum employment conditions documented – minimum wage compliance verified in PLN at the current exchange rate.
Assignment letter or addendum to the employment contract specifying the Polish posting terms, duration, and applicable law.
Health and safety induction completed in accordance with Polish regulations before work begins.

We obtained a clean PIP inspection outcome for a Swedish construction client in Małopolska (spring 2026). The employer had prepared all five items listed above before the first worker arrived. The inspector reviewed the file in under 30 minutes and raised no objections. Preparation of this kind costs a fraction of the time and expense involved in responding to a formal enforcement action.

One item that frequently falls through the gaps is the assignment letter. Many Swedish employers treat the existing employment contract as sufficient. It rarely is. Polish labour inspectors expect to see a document that explicitly addresses the posting, including the Polish host entity's name and address, the expected end date, and confirmation that Polish minimum conditions apply. If that document does not exist, the inspector has grounds to question whether the posting was properly structured.

Swedish employers planning assignments in Poland should also review their office arrangements. If the posted workers will use leased premises in Warsaw or another Polish city, the lease terms carry their own compliance dimensions – our guide on office lease review for Sweden tenants addresses the key points specific to Swedish companies entering the Polish market.

Two broader considerations apply to longer postings. First, if the assignment extends or a new project follows immediately, the employer must assess whether the 24-month ceiling has been reached across all related postings. ZUS and Försäkringskassan can look through formal breaks in posting to determine whether the overall arrangement was genuinely temporary. Second, if a worker eventually transitions from posted status to local employment in Poland, the employer will need to address work permit requirements – though EU nationals do not require a work permit in Poland, non-EU nationals employed by a Swedish company may face additional steps.

To receive an expert assessment of your company's posting compliance position, contact info@kordeckipartners.com.

Frequently asked questions

Q: Can a Swedish employer apply for an A1 certificate after the posting has already started?

A: Retroactive applications are technically possible but carry significant compliance risk. Försäkringskassan may issue the certificate with a start date matching the posting, but Polish authorities – particularly ZUS – may treat the period before the certificate was issued as uninsured in Sweden. This can result in a retroactive contribution assessment in Poland. The safest approach is always to obtain the certificate before the worker's first day in Poland. If a retroactive situation has already arisen, legal advice should be sought promptly.

Q: How much does the A1 application cost, and how long does it take?

A: There is no fee for the A1 application itself. Försäkringskassan processes most applications within 4 to 8 weeks. Straightforward cases with complete documentation can be resolved in 3 weeks. The PIP notification in Poland is also free of charge and is processed immediately upon submission. The main cost for employers is the time spent gathering documentation and – where professional assistance is used – legal fees for reviewing compliance across both Swedish and Polish requirements.

Q: Does the A1 certificate cover all social security contributions, or only some?

A: The A1 certificate covers the full scope of social security contributions under Swedish law – pension, health, unemployment, and related branches. While the certificate is valid, the employer pays Swedish contributions only; no Polish ZUS contributions are due on the same earnings. This is one of the principal practical benefits of the posting framework. However, the certificate does not affect Polish income tax obligations. Posted workers who spend more than 183 days in Poland in a calendar year may become Polish tax residents, which is a separate analysis and requires separate planning.

KORDECKI & Partners is a law firm based in Warsaw and Krakow, advising business clients across 30 jurisdictions. Our team combines expertise in Polish and international law with a practical approach to employment law, global mobility, and cross-border posting compliance. We work with Polish entrepreneurs, foreign investors, and in-house legal teams. To discuss your situation, contact info@kordeckipartners.com.