Each year in November SKAT generates a preliminary income assessment for you to review. The figures in your preliminary income assessment determine how much tax you have to pay during the year and allow you to make changes. You can access your preliminary income assessment during the year. Tax does not know your financial situation and what deductions you might have in form of transport, unemployment funds etc. so you yourself need to adjust your tax payment due to your financial situation.
Each year in March SKAT generates a tax assessment notice that tells you the status of your tax payment for the previous year. If you paid too many taxes, you will be reimbursed. If you paid too little, you will be required to pay the outstanding amount.
You can access your tax assessments via SKAT.dk using NemID. If you do not have a NemID, you can get one at nemid.nu or at the citizen service centre
See examples on how to do preliminary income assessment and Tax assessment notice at Skat.dk. Choose Preliminary income assessment or Tax assessment notice - and click on the videos to find a visual guide.