Withholding Tax in Denmark for Polish Temp Workers 2026

For Polish workers taking on temporary assignments in Denmark, understanding withholding tax in Denmark for Polish temporary workers is one of the most practical steps you can take before your first day on a Danish site. Known in Danish as kildeskat, this tax mechanism determines exactly how much of your gross wage is deducted at source each pay period, and whether you fall under full or limited tax liability to the Danish state. Getting it wrong can mean unexpected tax bills, penalties from SKAT, or delays in receiving refunds you are legitimately owed.

What Is Limited Tax Liability and When Does It Apply?

Danish tax law distinguishes between two categories of taxpayers. Full tax liability applies to individuals who are resident in Denmark, meaning they have established a permanent home or have stayed in the country for more than six consecutive months. Limited tax liability, on the other hand, applies to workers who live outside Denmark but earn income from Danish sources. For most Polish construction workers, tradespeople, and agency staff on short-term contracts, limited tax liability is the relevant category.

Under limited tax liability, you are taxed only on the income you earn in Denmark, not on your worldwide income. This is an important distinction, because it means your Polish salary, rental income, or savings interest are assessed separately by Polish tax authorities under the rules of ZUS and the Polish tax administration. The legal basis for this split lies in the double taxation agreement between Poland and Denmark, which follows the OECD model convention and determines which country has the right to tax which type of income.

If you are uncertain whether your situation qualifies as limited rather than full tax liability, the decisive question is always: where is your habitual residence? If your family, permanent home, and centre of life remain in Poland, and you travel to Denmark for a defined work period, limited tax liability almost certainly applies to you. Misclassifying yourself as fully liable when you are not can lead to overpayment, while the reverse error can trigger interest charges and enforcement action by SKAT.

Step 1: Check Your Eligibility Before You Arrive

Before you travel to Denmark, gather basic documentation confirming your Polish tax residency. A certificate of tax residency issued by the Polish tax office (Urząd Skarbowy) is the strongest proof. You should also have your Polish address registered with the local municipality, and if you contribute to ZUS, ensure your contribution records are up to date. These documents form the backbone of any later claim that your centre of life remained in Poland throughout the assignment. Managers coordinating cross-border teams should be aware of these requirements early; the kinds of administrative oversights that arise from poor preparation are covered in detail in our guide on 5 Costly Mistakes in PL-DK Construction Team Management 2026.

Step 2: Gather the Required Documents

Once you have confirmed that limited tax liability applies, you will need the following before registering with Danish authorities. You need a valid passport or national ID card, your Polish address and proof of residency, your employment contract or assignment letter from your Danish or Polish employer, and your Polish tax identification number (NIP). If you are posted by a Polish agency, ask your employer for a copy of the A1 certificate issued under EU social security coordination rules, which confirms you remain covered by Polish social security during the posting. This document is separate from the tax question but SKAT and Arbejdstilsynet may both ask to see it.

Step 3: Register with SKAT and Obtain a Tax Card

All workers earning income in Denmark must register with SKAT and obtain a skattekort (tax card), regardless of whether they fall under full or limited liability. You can start this process through the official SKAT self-service portal at skat.dk. You will need a Danish personal identification number (CPR number) to complete registration, which you obtain from the local municipality (borgerservice) in the area where you will be working or staying. Without a tax card, your employer is legally required to withhold tax at the maximum rate, which is significantly higher than the standard rate applied to limited-liability workers.

When completing the registration form, indicate clearly that you are a non-resident worker subject to limited tax liability. SKAT will then issue a tax card specifying your applicable deduction rate. Keep a copy of this card and provide it to your employer before your first wage payment. If your assignment extends beyond the initial period or your circumstances change, you must notify SKAT promptly, as the tax card is linked to a specific income estimate for the year.

Step 4: Submit Your Information and Confirm with Your Employer

After receiving your tax card, confirm with your payroll administrator or employer that the correct rate is being applied. In Denmark, the employer is responsible for deducting the right amount of kildeskat from each wage payment and remitting it to SKAT. If you are working through a staffing agency, check that the agency has your current tax card on file. Errors at this stage are common and can be difficult to correct retroactively, particularly if you return to Poland before the end of the Danish tax year.

Workers on rotating assignments should also be aware of how their tax situation interacts with holiday pay entitlements. The Danish Ferieloven governs holiday pay accrual, and for workers moving between employers or contracts, the rules can be complex. Our article on Feriepenge and Job Rotation: Holiday Pay for Polish Workers in 2026 explains how these entitlements work in practice.

Step 5: Wait for the Annual Tax Assessment

Each spring, SKAT issues an annual tax assessment (årsopgørelse) covering the previous calendar year. For workers under limited tax liability, this assessment covers only Danish-source income. If too much tax was withheld during the year, you will receive a refund. If too little was withheld, you will owe the difference. SKAT sends the assessment to your registered Danish address or, increasingly, through the digital post system. If you have returned to Poland by the time the assessment arrives, make sure you have arranged access to Danish digital services or appointed a representative to handle correspondence on your behalf.

Common Mistakes to Avoid

One of the most frequent errors is failing to register with SKAT at all, on the assumption that the employer will handle everything. While employers do have withholding obligations, the responsibility for correct registration ultimately lies with the worker. Another common mistake is not updating the tax card when income changes significantly mid-year, which can result in either underpayment or overpayment. Workers who are injured on site face an additional layer of complexity, as compensation payments may have different tax treatment depending on their legal classification. If you are ever in that situation, the guidance in our article on Workplace Accident in Denmark: Who Is Liable and What Steps Must a Polish Agency Take in 2026 is a useful starting point.

Finally, never assume that your Polish employer or posting agency has automatically handled your Danish tax registration. Under EU posting rules and Danish law, the obligation to register and pay kildeskat rests with the entity that pays your Danish wages. Verify this in writing before your assignment begins.

Actionable Advice for 2026

Before leaving for Denmark, obtain a tax residency certificate from your Polish Urząd Skarbowy and ensure your ZUS contributions are current. On arrival, register with the local borgerservice to obtain a CPR number, then complete your SKAT registration at skat.dk and request your tax card. Hand the tax card to your employer before the first pay date. Keep copies of all correspondence with SKAT, and after returning to Poland, monitor your registered Danish address or digital post account for the annual assessment. If you are owed a refund, you have the right to claim it, but you must act within the statutory deadlines set by Danish tax law. When in doubt, consult a qualified cross-border tax adviser familiar with both Polish and Danish rules, as the interaction between the two systems can produce unexpected results for workers whose assignments span more than one calendar year.