December 01, 2025

Bipartisan Warren, Cassidy Bill to Simplify Tax Error Notices Signed Into Law

Bipartisan Warren, Cassidy Bill to Simplify Tax Error Notices Signed Into Law

Washington, D.C. — The Internal Revenue Service Math and Taxpayer Help (IRS MATH) Act, bipartisan legislation championed by Senators Elizabeth Warren (D-Mass.) and Bill Cassidy (R-La.) in the Senate, was signed into law by the President.

“It’s common sense that the IRS should tell Americans where they made mistakes on their taxes,” said Senator Warren. “I fought hard to fix the law and simplify the tax filing process. Now, Americans will have more money in their pockets, without needing to spend a fortune on lawyers or hours to decipher confusing tax notices."

The IRS MATH Act ensures that when taxpayers make simple math or clerical errors on their taxes, the IRS sends them clear notices indicating where they made an error and laying out a 60-day appeal window.

Specifically, the bill:

  • Directs the IRS to improve notices of math or clerical errors, requiring that notices:
    • Identify the line item the IRS is changing;
    • Explain the reason for the change, and
    • Clearly list the taxpayer’s required response date.
  • Requires that the IRS notify the taxpayer of abatement determinations.
  • Requires the Treasury Secretary to provide additional procedures for requesting an abatement of a math or clerical error adjustment, including by telephone or in person.
  • Creates a pilot program coordinated by the IRS and National Taxpayer Advocate to determine the benefit of sending math or clerical error notices by certified or registered mail.

The U.S. House of Representatives passed the bill by voice vote in March. Representatives Brad Schneider (D-Ill.) and Randy Feenstra (R-Iowa) led the bill on the House side.

###