RUT Register Denmark: What You Need to Work in Denmark on Construction Sites

Going to work in Denmark on a construction site? Denmark has no national site ID card, but that does not mean you can just turn up. Before the first day, your company must be in the RUT register Denmark uses for foreign service providers (Registret for Udenlandske Tjenesteydere), and you need the right social security, tax and – if you weld, cut or grind – hot work papers. This guide goes one level deeper than our Nordic site cards overview and explains each registration and card for Denmark, who arranges it, the deadlines and what the Danish client will check.

Summary: registrations and cards for work in Denmark

RUT register Denmark: who must register and when

The Register of Foreign Service Providers (RUT) is run by the Danish Business Authority on virk.dk. Registration is required from the very first day of work – there is no minimum duration.

Who must register in RUT

• Foreign companies that post their own workers to do temporary work for a business or a private person in Denmark.
• Foreign self-employed persons without employees doing temporary work in general building and construction, or installation and repair of machinery and equipment.
• Foreign temporary work agencies that place workers with Danish user companies.

There are narrow exemptions, for example the "fitter rule" (montørreglen) for up to eight days of installing a technical facility. It does not cover general building and construction work, so a construction subcontractor should assume it must register.

Deadlines and what goes into the registration

• Deadline: no later than the moment work in Denmark starts.
• Changes (new site, new dates, new contact person): by the first business day after the change.
• Content: one service per contract with exact start and end dates, every workplace address (or coordinates) with its period, the sector codes, and a contact person who works in Denmark on the job, with mobile number and email.
• From 1 January 2026: for posted workers who are not EU/EEA or Swiss citizens, the company must also upload the agreement with the Danish client, the employment contracts and the residence and work permits.

Documentation to the Danish client

Give your Danish client (the main contractor or customer) proof of registration – in practice the RUT registration confirmation with your RUT number – before or on the first day. In building and construction the client must notify the Danish Working Environment Authority (Arbejdstilsynet) if it has not received this documentation within three days of the start, and the client can be fined if it does not. Clients can also check the register themselves, so most main contractors simply refuse to let an unregistered crew start.

Fines and checks

Late registration or a late change report can mean a DKK 10,000 fine, and failing to register can lead to sanctions from Arbejdstilsynet. Since 1 January 2025 the foreign company must also make sure that every employee can show valid identification to Arbejdstilsynet during an inspection – so keep your passport or national ID card with you on site.

A1 certificate: social security while posted

If you stay employed by your company at home and are posted to Denmark, you normally remain insured in your home country. This is proven by the PD A1 certificate, which your employer requests from the social security authority in your home country before the posting. A posting can last up to 24 months; longer is only possible by agreement between your home authority and Udbetaling Danmark. Bring your European Health Insurance Card (EHIC) too – together with the A1 it gives you access to necessary public healthcare in Denmark.

Tax card (skattekort), personal tax number and CPR

Tax depends on how you work in Denmark:

• Employed by a Danish company: you need a tax card (skattekort) before your first payslip. Apply online, with form 04.063 "Apply for tax card and Danish personal tax number", or in person at an International Citizen Service centre. Bring a signed employment contract and photo ID. If everything is complete, you receive a preliminary income assessment (forskudsopgørelse) within about two weeks. For stays of up to six months (EU/EEA citizens) you get a personal tax number; if you stay longer you need a CPR number.
• Hired out to a Danish business (you live abroad, your employer is foreign and you work for a Danish company): Danish hiring-out of labour tax applies – 8% labour market contribution plus 30%, in total 35.6% of gross pay. The Danish business pays it, and you usually do not need a CPR number.
• Posted by your own company to carry out a contract: stays under six months are normally taxed in your home country, but check your situation with Skattestyrelsen.

EU residence document (EU-opholdsdokument) if you stay more than 3 months

EU/EEA citizens who plan to stay in Denmark for more than three consecutive months need an EU residence document from the Danish Agency for International Recruitment and Integration (SIRI). Fill in form OD1A and book a SIRI appointment with your passport or national ID card and proof of accommodation. The residence document is not the same as CPR registration: afterwards you apply for a CPR number separately, which can take two to three weeks. You can stay up to six months without CPR registration, but after that it is required.

Hot work certificate (varmt arbejde certifikat)

Welding, cutting, grinding with an angle grinder, soldering and torch-on roofing count as hot work (varmt arbejde). A varmt arbejde certifikat is not required by law, but most Danish insurers require hot work to follow DBI's guideline (Brandteknisk Vejledning 10), and many building sites check the certificate at the gate.

• Course (varmt arbejde kursus): one full day (7.4 hours) with a certified instructor, theory, practical fire-extinguishing exercises and a final test. DBI states that certificates from pure e-learning courses are not accepted.
• Validity: the DBI certificate is valid for 5 years and comes as a physical card or in an app.
• Language: DBI also runs the course in English, including a roofing version recognised across the Nordic countries.
• Before each job: insurers usually require notice before hot work starts, and a fire watch (brandvagt) may be required.

If a fire starts during hot work done without a valid certificate, the policyholder can face a higher deductible – another reason main contractors insist on seeing it.

Site induction and the work environment coordinator

When two or more companies work on a site at the same time, the client (bygherre) must appoint a work environment coordinator (arbejdsmiljøkoordinator, often called the "sikkerhedskoordinator"). On sites with 11 or more people the coordinator draws up a safety and health plan (plan for sikkerhed og sundhed, PSS) and holds safety meetings at least every 14 days. Every company on site must attend these meetings – including foreign subcontractors and self-employed workers without staff. Your own employer must instruct you in the site risks and the work you will do, and the main contractor normally gives a site induction on day one.

Do workers need the arbejdsmiljøuddannelse?

No. The mandatory work environment training (arbejdsmiljøuddannelse) is for members of the company's work environment organisation – the elected safety representative and the manager – who must complete it within three months. Ordinary workers do not need it. Note, however, that a company with five or more employees on a Danish site for at least 14 days must set up such an organisation on site.

Before you travel: checklist

1. Check that your company has registered the job in RUT and that you have the RUT confirmation to show the Danish client.
2. Ask your employer for your PD A1 certificate and pack your EHIC card.
3. Clarify how you are taxed; if you are employed in Denmark, apply for a tax card (skattekort) with form 04.063.
4. Staying more than three months? Book a SIRI appointment for the EU residence document, then apply for CPR.
5. Doing hot work? Take a one-day varmt arbejde kursus and keep the certificate (card or app) with you.
6. Carry your passport or national ID card on site every day.
7. Ask the main contractor about their site rules, induction and any access card – see the overview of cards in Finland, Sweden, Norway and Denmark if your crew moves between countries.

Protective equipment you'll need on site

Danish main contractors usually expect a helmet, hi-vis clothing, safety boots, safety glasses and the right gloves for the task. The details are in our guide to PPE requirements on Danish construction sites, and you can compare countries in Nordic construction-site PPE rules compared. Shop hi-vis workwear, safety boots, safety helmets, safety glasses and work gloves. For hot work, add flame-resistant workwear and leather welding gloves. To equip a whole crew, use the workwear kit builder – delivery takes 8–16 days, so order before you travel.

FAQ

Do I need a site ID card to work in Denmark?

There is no national construction ID card in Denmark. Some main contractors issue their own access cards, and you must always be able to show valid ID such as a passport or national ID card.

Can I register in RUT after I start working?

No. The registration must be in place no later than when work starts. Late registration can be fined DKK 10,000, and the client must report missing documentation to Arbejdstilsynet after three days.

Is the RUT registration my job as a worker?

No, if you are employed: your employer registers the service. Only self-employed persons without employees register themselves – in construction they always must.

How long is the varmt arbejde certificate valid?

The DBI hot work certificate is valid for 5 years. After that you take a new course. Certificates from e-learning only courses are not accepted by DBI.

Do I need an EU residence document for a two-month job?

No. The EU residence document from SIRI is needed if you stay more than three consecutive months.

This guide is general information, not legal advice. Rules and prices change – always confirm with the issuing authority or your main contractor before you travel.