Rakuten Affiliate is required by US tax laws and the Internal Revenue Service to collect a social security number (SSN) or employer identification number (EIN) for tax purposes. Without this information, Rakuten Affiliate will be unable to issue payments.
Per the IRS, Rakuten Affiliate is required to collect and report annually the information for individuals to whom commissions are paid. Without either an SSN or EIN, Rakuten Affiliate would be required to do a “backup withhold” of 24% on publisher commission payments for tax purposes.
For more information about IRS requirements please see these resources: