In 2011, the Treasury Inspector General for Tax Administration (TIGTA) reported that individuals who were not authorized to work in the United States received $4.2 billion by claiming the refundable portion of the child tax credit—the additional child tax credit (ACTC). The ACTC is available to working families with children under age 17. The report sparked considerable concern that unauthorized aliens were obtaining refundable tax credits. The TIGTA audit was based upon an analysis of tax returns filed by persons with Individual Taxpayer Identification Numbers (ITINs). The Internal Revenue Service (IRS) issues ITINs to individuals who are required to have a taxpayer identification number for tax purposes but are not eligible to obtain a Social Security number (SSN) because they are not authorized to work in the United States. All aliens, including those who are in the country illegally, are generally subject to federal taxes under the Internal Revenue Code (IRC), and even income illegally obtained is subject to taxation.
A refundable tax credit is one where the taxpayer may receive a payment from the IRS that exceeds his or her tax liability. Examples include the earned income tax credit (EITC), the additional child tax credit, the American opportunity tax credit, and the health coverage tax credit. While the EITC requires SSNs of all recipients, the other existing credits, including the ACTC, do not. Similarly, several now-expired credits included an SSN requirement, while others did not. Apart from any SSN requirement, the IRC also expressly prohibits nonresident aliens from claiming some refundable credits.