1. The Foreign Account Tax Compliance Act (FATCA)
The most significant architect of this system was the 111th United States Congress, which passed FATCA in 2010. It was introduced by Representative Charles Rangel and Senator Max Baucus, and signed into law by President Barack Obama. While FATCA was originally aimed at "foreign financial institutions" (banks), it effectively turned any large corporation that moves money across borders, like Amazon, into a mandatory reporting agent. Under FATCA, Amazon must identify "US Persons" for the IRS globally or face a 30% penalty on its own corporate transactions. See defintion of "person" below.
2. The Internal Revenue Service (IRS)
2. The Internal Revenue Service (IRS)
The IRS specifically designed the W-9 and W-8 series forms and the automated "Tax Interview" infrastructure that you see on the KDP dashboard. They issued regulations under Title 26 of the US Code that require "Withholding Agents" (Amazon) to collect a Taxpayer Identification Number (SSN or EIN) before making payments. The IRS created the legal liability that forces Amazon to choose between interrogating you for an SSN or paying massive fines to the US Treasury.