This job was over $2,500 and now client asking for my social security number. Feels odd providing that to a stranger. Is it ok to give it to them or is there another way for them to handle their taxes? I know they need a w-9 to generate a 1099 for me. The w-9 requires a SSN or Federal Tax ID number. So maybe I will just register as a sole proprietor and then use a Federal Tax ID instead.