advance payment of personal income tax

We have answered your question in a video: https://youtu.be/R7pfKWzcrDQ</

As a self-employed person, you do not have to pay taxes if you have made a tax loss. This means that you do not pay personal income tax on your self-employed activity.

Do you also receive a salary as an employee? Then you can offset that loss against your salary, which means you pay less taxes.

If you have made advance payments, you will receive a refund via your tax return (personal income tax return).