If you want to be insured against unemployment in Denmark, you have to take out unemployment insurance with an unemployment insurance fund (A-kasse). These are private organisations that are often linked to specific labour unions. You do not have to be a member of a particular labour union, however, to take out insurance with a particular unemployment insurance fund.

In order to receive unemployment benefits, you must
• have been a member of an unemployment fund for at least one year
• be able to take up work with one day’s notice (and have the right to reside and work in Denmark)
• have had a certain minimum income (in total) during the last 3 years (while being a member of an A-kasse).

For more information about unemployment insurance and the requirements, see the official websites of lifeindenmark.dk and the European Commission.

You can find a list of unemployment insurance funds (in Danish) here.