Federal law requires all companies/individuals to hire contractor (freelancers) on W9 unless they are foreigners (international residents, non-us citizens, non-immigrants) , for which W8 form has to be submitted. I see a lot of freelancers do away from big projects that require contractor’s US tax id to work (especially for w9 purpose). But one thing most of them do not know is the fact that they can hire foreigners on W8 bases. W8 works equally well as W9 for tax filing. W8 is designed for US residents to hire foreign resources working off shore.
Next time when you were asked to submit W9, request your client to process W8 instead. W8 entitles you to pay taxes in your home country.