If you are a U.S. citizen, U.S. resident, or owner of a U.S.-based business, we need your tax ID or social security number (SSN) when you sell your book for a profit because we’re required to report your earnings to the IRS.
In the U.S. if you make over $600 in a calendar year through sales of your book, Reischling Press Inc (RPI) is required to file a 1099 with the IRS. (RPI is Blurb and MagCloud's parent company and will be listed as the Payee on your 1099). RPI does not withhold taxes from your payments so you’re responsible for paying any required taxes on your profits.
And don't worry, the information you provide us, including sensitive information like social security numbers required for author payment details, is completely safe. Any such data is securely encrypted.