The tax settings for your publisher account are stored on the "Publisher account and payment settings" page (first option under ACCOUNTING on your Publisher Hub page). On this page you elect whether you should receive a 1099 from OneBookShelf at the end of each calendar year or if you are exempt.
If you are a US entity (individual, partnership, Limited Liability Company, Limited Partnership or Estate) that is not a regular corporation then you should elect to receive a 1099 and provide your information. This also includes US citizens living abroad and non-US citizens residing in the USA.
If our payments to you in a calendar year exceed $600, then we will send you a 1099-MISC form by the end of January in the following year, and we will file that form with the IRS.
If our payments to you in the calendar year do not exceed $600, then you will not receive a 1099.