Hi,
Thanks to all for your answers so far.
I am not sure if it is not allowed. But I know it does not fit to the criteria of "ondernemerschap". That means we cannot benefit from these nice heffingskortings but this is a side job, so I would not be able to claim it anyway. Maybe you are confusing these two?
As for the income tax, I am still puzzled. Having this as the second job, I guess since this is a "eenmanszaak" the income from this job would top up my income from my day job and I have to pay from a higher tax band. Is this true? Or do you count the company as a separate legal person and pay income tax from the lowest band?