Tillaeg on Danish Construction Sites: Mandatory Pay Supplements 2026

For any Polish worker stepping onto a Danish construction site, understanding tillaeg, the various pay supplements built into Danish wage agreements, is just as important as knowing the base hourly rate. These additions are not optional bonuses left to an employer's goodwill; many of them are contractually or legally required, and failing to claim or pay them correctly can lead to disputes, back-pay claims, and complications with both Danish and Polish tax authorities. This guide walks through which tillaeg are mandatory, how eligibility works, what documents you need, and how to settle everything properly in 2026.

What Is a Tillaeg and Why Does It Matter?

The Danish word tillaeg simply means "supplement" or "addition." On construction sites, it refers to a family of extra payments on top of the basic hourly wage. Some flow from national legislation, but the most important ones are defined in collective agreements, known as overenskomster, negotiated between trade unions such as 3F Byggegruppen and employer organisations. Because Denmark has no statutory minimum wage in the traditional sense, the overenskomst is effectively the law of the site. Any agency or direct employer posting Polish workers to Denmark is bound by the terms of the applicable agreement under the principle of equal treatment established in the EU Posted Workers Directive.

Danish labour market rules are overseen by Arbejdstilsynet, the Danish Working Environment Authority, which can inspect sites and verify that workers receive correct pay. The Ministry of Employment (Beskæftigelsesministeriet) publishes guidance on posted workers' rights and the applicable Danish rules.

Step 1: Check Which Tillaeg You Are Eligible For

Eligibility depends on the type of work, the hours worked, and the conditions on site. The most common categories of mandatory tillaeg on Danish construction sites include supplements for dirty or hazardous work, supplements for working at height or in confined spaces, overtime supplements, evening and night shift supplements, and travel or distance allowances. Weekend work almost always triggers a higher rate. The exact percentages and thresholds are set in the relevant overenskomst, so the first practical step is to identify which collective agreement covers your employer or the client company on that specific site.

If you are employed through a staffing agency, the agency is responsible for applying the correct agreement. If you are unsure, ask your shop steward (tillidsmand) or contact 3F directly. Workers on short rotations should also check their social security status, correctly issued A1 certificates determine where contributions are paid, and this directly affects net pay calculations. For a detailed breakdown of contribution rules, see our guide on ZUS Contributions for Seasonal Construction Workers in Denmark 2026.

Step 2: Gather the Required Documents

Before you can verify or dispute a tillaeg payment, you need the right paperwork. At minimum, collect your written employment contract or posting letter, the applicable overenskomst excerpt (your union or employer should provide this), payslips for every pay period, and time records showing when and under what conditions each hour was worked. If your site work involved hazardous materials, working at height, or night shifts, keep a personal log with dates and hours. Danish courts and arbitration panels rely heavily on contemporaneous records, so a simple notebook entry made at the end of each shift carries real evidential weight.

For Polish workers, ZUS documentation is equally important. Your A1 certificate confirms that you remain subject to Polish social insurance, which affects how gross-to-net calculations work on your Danish payslip. Workers who have contracts with more than one agency at the same time face particular complexity here, the article on A1 Certificate for Workers at Two Agencies: Avoid Double ZUS 2026 explains how to avoid paying social contributions twice.

Step 3: Calculate and Record Each Supplement

Once you have the overenskomst and your time records, the calculation itself is straightforward in principle. Take the applicable base rate, identify the supplement percentage or fixed amount specified in the agreement for each type of work condition, and apply it to the relevant hours. For example, if a hypothetical worker completes ten hours of documented work in a confined space during a week where the agreement specifies a particular dirty-work supplement, those ten hours should appear on the payslip with the supplement clearly itemised, not merged silently into a flat hourly rate.

Keep a running spreadsheet that mirrors your payslip. If the numbers do not match, you have a concrete basis for a conversation with your employer or agency before the issue grows into a formal complaint. Agencies handling large rotating crews can automate much of this reconciliation, the guide on How to Automate Worker Rotation Billing: 2026 Guide for Agencies covers the tools and workflows that make this manageable at scale.

Step 4: Submit Claims Through the Right Channel

If you believe a tillaeg has been underpaid or omitted, the process depends on whether a union is involved. Workers covered by 3F can raise the matter with their local union representative, who will initiate the formal grievance procedure set out in the overenskomst. Non-unionised workers can file a complaint with Arbejdstilsynet or seek advice from the Danish National Labour Market Authority. Keep all correspondence in writing, reference specific payslip dates and amounts, and attach your time records.

For Polish workers, the Państwowa Inspekcja Pracy (PIP), the Polish Labour Inspectorate, can also provide guidance on cross-border postings and has bilateral cooperation channels with Danish authorities. More information is available at pip.gov.pl. If the dispute involves undeclared income or incorrect tax withholding, the Danish tax authority Skattestyrelsen should be informed, as supplement payments are taxable income in Denmark.

Step 5: Wait for the Result and Follow Up

Formal wage disputes under a collective agreement typically follow a defined timeline set in the overenskomst itself. Arbitration panels generally aim to resolve straightforward cases within a few months, though complex cross-border posting disputes can take longer. While waiting, continue documenting your ongoing work and pay. If the matter is not resolved within the timeframe specified in the agreement, the union or your legal representative can escalate to the Labour Court (Arbejdsretten).

Common Mistakes to Avoid

One of the most frequent errors is accepting a flat all-inclusive hourly rate without checking whether it genuinely covers all the tillaeg you are entitled to. An all-in rate is only valid if it demonstrably exceeds what the overenskomst would pay when all supplements are added. Another common mistake is failing to register night or weekend hours separately, making it impossible to prove entitlement later. Workers who switch sites mid-week sometimes forget that a different overenskomst may apply on the new site, triggering different supplement rules from day one.

Finally, do not overlook the interaction between Danish tillaeg and Polish tax obligations. Supplement payments form part of your gross income and must be declared correctly to both Skattestyrelsen and, where applicable, the Polish tax authority at podatki.gov.pl. Getting this right from the start saves considerable administrative effort when the annual settlement arrives.

Practical Takeaway

The single most effective action you can take today is to obtain a copy of the overenskomst that applies to your current site, compare its supplement schedule line by line with your last three payslips, and raise any discrepancy in writing with your employer within the current pay period. That proactive step, grounded in the actual agreement rather than assumptions, is what separates workers who receive every kroner they are owed from those who discover shortfalls only after the contract ends.