Last year I was working for one very rude vendor. He hired me back in January and I asked him to sign some kind of agreement proving that I worked for him. All work has been done remotely, I was in Chicago and he was in California. He didn’t have any information about me. After working one month for him I quit, he paid me around $950 and we have never talked until his accountant reached out to me ( she used wrong last name) and requested me to provide W-9. Can I refuse providing this form to them?
Unfortunately, I think you are on the hook as he paid you $950. IIRC, if it were under $600, it wouldn’t be required, but at $950, they are required to report it.
You could refuse to send them the W-9, but you may cause yourself more trouble from them by doing it. You owe the taxes on the $950, whether you give them a W-9 or not, of course, and they may chose to hassle you a fair bit for the info if you don’t provide it. Best to just give them the W-9 (which of course they should have made you provide at the start of the contract, rather than after it’s over).