When you leave Denmark, there are a number of practical matters you must pay attention to
If you move from Denmark to your home country or to another country, you must report the relocation to the Civil Registration System (CPR). This can be done by filling in a leaving form and submitting it to your municipality of residence. Show up in Citizen Service (Borgerservice) to receive the leaving form and further information
You must also hand over your health insurance card.
If you move abroad for less than six months, you can retain your registered address unless you rent out or lend your house or flat.