I'm so grateful to great people who post on the Internet. How else would a British author find out how to get an exemption number so that they don't have to pay US tax at 30% on their e-books?.
I am in the happy position of being owed money for e-book sales by both Kindle and Smashwords, but they are American publishers, and I am a UK author. When I published my e-books, I ticked the boxes that said 'don't send me any money yet'. This is because if they pay a UK author who isn't registered with Uncle Sam, then they have to withhold tax at 30%. So I thought, I'll sort it out later, and promptly forgot about the whole thing - until I checked my balances and hey! Diddle dee dum. I've got royalties coming to me!
Of course, I'll have to pay UK tax at 20%, but a short session with my calculator and some sums that made my fingers inky convinced me that it was worth getting an ITIN number.
Smashwords very helpfully tell you what an ITIN is and have a link to the US government website where you can download form W-7. Then I Googled to see what other authors were doing. Two (sorry, lost the links, but you can Google them too) very helpfully detailed the whole process. I filled in the W-7 form the way they suggested and sent it off with my passport to the American Embassy in London. A couple of days later a letter, addressed to 'Dear Taxpayer', came back saying they were happy with the documents and had sent them off to America to be processed. Thank you, fellow authors.
Two extra notes for UK authors who want an ITIN number:
1. You need TWO special delivery envelopes - one to get your passport to the embassy, and one to have it sent home again.
2. Send off for your number NOW! My letter says that the ITIN number will take 4 months to arrive - and then I have to fill in another form and send that to the publishers, so I should have started this process last year some time.
It'll be so nice to be paid, though. I love royalties!