Can I write off expense money that my business pays to workers who have no supplied a W-9?

Is it possible to write off the money used to pay these workers or can I only write it off if I have collected a W-9? This is for a very small business.

Can I write off expense money that my business pays to workers who have no supplied a W-9?
If you are paying workers, you better get a w-9. You can write off all payroll expenses regardless. If you pay anyone more than $600 you need to give them a w-2 or 1099 as well.