'Who' is doing work is hard to enforce. 'How you pay them' is easy. Most businesses do not handle enough cash to be able to pay a lot of staff off the books, a

'Who' is doing work is hard to enforce. 'How you pay them' is easy. Most businesses do not handle enough cash to be able to pay a lot of staff off the books, and if you are doing it through the regular financial system, the tax man will find it very easy to make sure that you pay your dues.