Royalty payments you make generally are paid at the contracted amount with no taxes withheld. At tax time you will report those payments to the IRS and to the entities/person's you paid those royalties to on 1099-MISC in box 1 of that form if the total amount paid to any one individual exceeds $600.
You will "REQUIRE" to have the payee's SSN or ITIN in order to issue the 1099-MISC and if you don't, you will pay a penalty for each one you don't have. Before you make the first royalty payment you should send the intended recipient of such payment an IRS Form W-9 and require them to return it to you filled out, as a condition of payment. Get the blank form at https://www.irs.gov/pub/irs-pdf/fw9.pdf
