Some professions are regulated by law in Denmark. If you are to work within one of these professions, you must have a Danish authorisation.
It is an advantage to apply for authorisation before you arrive in Denmark as it takes time before you receive a reply to your application.
If you are a citizen of a country outside of the Nordic region, the EU/EEA or Switzerland, in some situations you must attach a Danish authorisation when you apply for a residence and work permit. For example, this applies if you are going to work as a doctor, dentist or school teacher.
The authorisation is issued by the authority that is responsible for the relevant area. Thus, there is a difference as to which documentation you must submit and how long it will take before your application is processed.
Please note that the requirements for authorisation depend on whether you are a Nordic citizen, an EU/EEA or Swiss citizen or whether you are a citizen of another country.
You can find more information about the rules for authorisation on the Danish Agency for Higher Education's website, where you can also find targeted information for Nordic, EU/EEA or Swiss citizens as well as citizens of other countries.