My grandfather lives in South Africa and is currently writing a book for an American publisher. He has been given the W-8BEN form to fill in but has no idea which tax treaty article to fill in to exempt him from federal tax. 0% should be with held. He is 81 years old, a pensioner and can't research these things on his own. Your help would be much appreciated, even if you just know of a website where I could look up the articles for him. Thank you.

Article 14 of the U.S.-South Africa Tax Treaty applies in your grandfather's case.