Taxation in Denmark is higher than in most other countries, mainly because it pays for a welfare system with good living conditions for all residents, whatever their income.  Income taxes are usually deducted at source by the employer, and VAT at the rate of 25% of the price is added to goods and services. 

There is a taxation agreement between Poland and Denmark, which means that people pay their tax in one country or the other; but almost all people employed in Denmark have to pay tax in Denmark. 40% of the taxes collected are directed to social benefits.  Social security benefits include the following:

(i) Medical care, treatment in hospital, maternity care, cash sickness benefit and rehabilitation

(ii) Benefit for accidents at work and occupational diseases 

(iii) Early and ordinary retirement pension, and supplementary pension;

(iv) Pension also covers invalidity 

(v) Death grant 

(vi) Unemployment benefit 

(vii) Family benefit 

In general, people entering Denmark acquire entitlement to health care and free hospital treatment only after they have been in the country for six weeks.  As a precaution, it is recommended that you obtain private insurance to cover your first six weeks in Denmark.

Customs and Tax website