So..like the title says, do you legally need to get an ITIN if you are an international author who has had a book published by a US publisher? I understand without it, I'm losing out on 30% of my royalties. However, I've only had one thing published and it is no longer available, and was only available for a couple months. The amount of money I would need to spend obtaining documents needed to apply for the ITIN is WAY more than the 30% I would be receiving in return. So is that the only reason, or am I legally obligated to obtain an ITIN?