Self-employed in a secondary occupation. How much do I actually have left?

I think it all goes into one big pot for your personal income tax.

Of course you can deduct it (actually, you add your losses to the 'profits' from your main occupation).
I think income and expenses are included separately in personal income tax, aren't they?
You don't actually have your gross salary from your self-employed business, because you made a loss. Maybe there was just a little more in your bank account.
It's all yours anyway; all the money in your bank accounts, including your losses as well as your profits.

Hi, if you don't make a profit, you don't paid vAT on it, of course, because you have entered more costs than you have earned back. For your personal income tax, your salary from your main occupation and your profit/loss from your secondary occupation are added together and you are taxed on that. So if you earn €40,000 in your main occupation and make a loss of €10,000 in your secondary occupation, you will be taxed on €30,000 in your personal income tax. If that €10,000 is a profit instead of a loss, you will be taxed on €50,000. This means you may fall into a higher or lower tax bracket depending on the turnover of your secondary occupation. If you make a loss, make sure you do not continue to make losses with your secondary occupation for four or five years in a row, otherwise the tax authorities may start asking questions. Kind regards, Jef