No Social Security number? No problem.

The IRS paid out billions in refundable tax credits to undocumented immigrant workers last year, according to a new Treasury audit.

Federal law bars illegal immigrants from collecting tax benefits, like the Earned Income Tax Credit, that can be claimed by residents with Social Security numbers. But the Treasury report found that the tax code’s lack of clarity is allowing the Additional Child Tax Credit (ACTC), which reduces taxes owed by certain individuals with children, to be heavily claimed by undocumented workers;if their tax bills dip below zero, they can collect government checks.