I haven't worked on the money side of a business - businesses are allowed to claim an expense for purposes of reducing their income tax burden, but they don't h

I haven't worked on the money side of a business - businesses are allowed to claim an expense for purposes of reducing their income tax burden, but they don't have to pay sales taxes on that same expense if it's internal to an associated business? That seems perverse. "I spent money on X" "Okay where's the sales tax payments for X?" "The money went to myself, so there's no sales tax" "So then you didn't spend the money?" "Yes I did."