Deduct Income Tax
You should withhold income tax from his salary....yes I know its a contract, but the tax colllector will conisder it a salary, unless of course its a company. But if its a person, and your condo doesn't withhold, you could be liable if he doesn't pays his taxes; of course, if either is caught, which is near to impossible, since the tax collector go after the big cats mostly.
You could also ask a Dominican Accountant, which I am not.