I work full time and now have a part-time job from my laptop. I can earn as much as I want or it varies totally. I think I shouldn't earn more than 400 a month, but do I have to state that somewhere? Or I need a trade license for this. I can work freely and have no fixed times
Of course you have to register that.
Sounds strange… Normally, your employer will register you with the social security and also pay tax.
What kind of job is that?
I help set up websites online
A part-time job, you have an employment contract there - on a mini-job basis. This counts towards your income and will be recorded in the next tax return for the next year
I now have (from the laptop)
a part-time job
then do you also have an employer? Who does a payroll? And register with social security? And withholding income tax? And leads away?
If not, you should find out for what, whom and under what conditions you work at all.
I help to set up websites online
So are you doing a self-employed job?