Earlier quoted context omitted.
Yes you have to file an IR3 if you make other income. http://www.ird.govt.nz/income-tax-individual/end-year/ir3/ii... My favourite part of our tax system is the advice to file if you have "income from an illegal enterprise" EDIT: Just as a reply to the original point. I'm not sure how complicated the US system is. I'm not trying to say it's bad either, it just seems to me that we have a system similar to the one that…
This advice is probably not explicitly given by the IRS, but it is what any decent tax attorney will tell you. They got Al Capone not for his other crimes, but for tax evasion.
"Income from illegal activities, such as money from dealing illegal drugs, must be included in your income on Form 1040, line 21, or on Schedule C or Schedule C-EZ (Form 1040) if from your self-employment activity."
"If you receive a bribe, include it in your income."
"You must include kickbacks, side commissions, push money, or similar payments you receive in your income on Form 1040, line 21, or on Schedule C or Schedule C-EZ (Form 1040), if from your self-employment activity."
"If you steal property, you must report its fair market value in your income in the year you steal it unless in the same year, you return it to its rightful owner."