Sometimes I do very short term work as a contractor (like one or two days). Sometimes companies insist I use their template for filling out my invoice. Some insist they need my SIN (SIN is Canada's version of SSN) but this is wrong because I'm a contractor and they're not taking off tax. When I tell them this it just falls on deaf ears and they say "we need it". In these types of situations where the company is insisting they need some personal information and it's not worth hiring a lawyer to fight, is there anything that can be done? In another example a company wouldn't pay me until I filled out a tax form that wasn't even the right one.