This is an issue for experts.
I take that you are going to work in a big international company which can put such expertise at your disposal. I would absolutely ask for such help. If you don't want to ask for it, then I'll recommend you to contact SKAT as the second choice.
https://skat.dk/skat.aspx?oid=8544http://skat.dk/skat.aspx?oid=3106&ik_navn=transporthttp://icitizen.dk/
... contribution towards ATP...
https://indberet.virk.dk/sites/default/ … somhed.pdf
As you see, the amounts are much less here.
The mentioned amounts is part of the company's pension scheme. Normally, your amount can be deducted in your income before taxation as the money isn't available before you retire in a far future, and at that time the pension will be taxated. In addition to the normal praxis, expats have the possibility to take the saved pension amounts with them as a sum when they leave the country. If they prefer to do this, the pension contributions will be taxated along with the monthly pay. So you have to do a choice.
If you rent out your house in Belgium for more than 12 months, the rent will be regarded commercial rent, and you shall choose between the methods of accounting. Despite what kind of method you choose, the net income will be taxable. It depends on any expenses.
http://skat.dk/skat.aspx?oid=2234797
As long as you are in Denmark, all income will be taxated here, but of course with regard to a double taxation agreement.
Then you mention the tax scheme for highly-paid employees. If you choose this scheme, the taxable income is without deductions, e.g. you cannot profit from your wife's unused personal deduction (which will be 46,000 kroner as long as she doesn't work). And the first year, you'll not be entitled to holiday without paying for it yourself as the holiday earning year goes from January 1 to December 31 the year before. This means that your income the first year will not consist of 12 months, but less.
As there are so many unknown factors, I have made some rough calculations based on the fact that you are married and have a child under 18 years. Living in the municipality of Copenhagen. 2018.
Your income 800,000 kroner Your income 800,000 kroner
Rent 90,000 kroner Rent 0
Wife doesn't work Wife doesn't work
Tax 355,325 kroner Tax 322,825 kroner
Your income 800,000 kroner Your income 800,000 kroner
Rent 90,000 kroner Rent 0
Wife 450,000 kroner Wife 450,000 kroner
Your tax 371,862 kroner Your tax 339,361 kroner
Your wife's tax 160,037 kroner Your wife's tax 160,0137 kroner
http://www.tastselv.skat.dk/fskbrgn2/Skprofil.aspx
A long question requires a long answer, and my answer is long, but if it is elaborated enough, I don't know. Your rent won't be 90,000 kroner without deduction, but anyway, I chose the gross amount.Taxation is a complicated thing, and especially when we talk double taxation agreements, foreign income ........................ The list is long. However, if you think we/I can be of more use, don't hesitate bringing up your questions.
/Nellie