The U.S. IRS has published a practice unit, Erroneous Claim for Refund or Credit Penalty. The process overview of the practice unit includes the following: Congress enacted IRC 6676 to allow penalties for erroneous tax refund or tax credit claims. The penalty may be imposed on a taxpayer filing an original return, an amended return, a claim, or any other form or writing that contends the taxpayer made an overpayment of tax. In the "Protecting Americans from Tax Hikes (PATH) Act of 2015," Congress amended IRC 6676 in three key ways: to remove the exception for erroneously claimed earned income...