Under My Account tab in Adsense, there is a Tax Information section where it requires publishers to submit tax information. This is the question they ask there:
Simply choose No, and your tax information is submitted!Are you a U.S. citizen, U.S. resident alien, U.S. corporation, or a U.S. partnership?
Yes No
*Please note, if you've any commercial/financial activities in the USA, you'll must submit valid tax information. These activities do not include using any email/blogging/hosting services such as Blogspot or Gmail.
So, cheers and have a tension-free earnings from home!