A-kasse vs. union: what's the difference?

The a-kasse is insurance against unemployment. The union (fagforening) helps while you have a job. They are separate, and you can have one without the other.

Union (fagforening)A-kasse
Helps youWhile employedWhen unemployed
Pays benefitsNoYes, up to DKK 22,041/month
Price per monthDKK 69-694DKK 513-579
Tax deductionUp to DKK 7,000/yearFull amount

Traditional unions (HK, 3F, IDA, Djøf and others) negotiate collective agreements for their profession. "Yellow" unions (Det Faglige Hus, Ase, Krifa, Frie) accept everyone, do not negotiate agreements and cost from DKK 69 per month.