Last week, President Trump signed a new law, the Internal Revenue Service Math and Taxpayer Help (IRS MATH) Act, designed to simplify at least this one part of our complicated tax code.

The legislation was bipartisan: sponsored by Sens. Bill Cassidy (R-LA) and Elizabeth Warren (D-MA) in the Senate and Reps. Randy Feenstra (R-IA) and Brad Schneider (D-IL) in the House, and approved unanimously by both chambers.

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In the modern era, the IRS feeds all of the tax returns it receives through a computer program, which automatically flags if someone added things up wrong. When that happens, the IRS then sends a “math error notice” to the taxpayer; the agency also sends such notices for other mistakes that are easily fixed, like if someone put the right information in the wrong place, if a return is internally inconsistent, or if someone gives the wrong Social Security Number or forgets to include one entirely.

About 2 million of these notices are usually sent out each year — although, as you can see below in this chart by the Tax Policy Center, that number skyrocketed to 17 million during the pandemic (primarily because of errors people made in claiming stimulus checks and the expanded Child Tax Credit).

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If someone receives a math error notice in the mail, they have 60 days to quibble with it. If they don’t appeal within that timeframe, they are considered to owe the corrected amount the IRS is asking for. When everything works well, this is a win-win for the government and for the taxpayer: there’s no reason for either side to go through a more drawn-out and expensive audit or legal process if the only issue is that John wrote “$3,650” where he meant to put “3,506.”

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For each of the last four years, Collins has proposed that Congress pass a law telling the IRS to fix their math error system, so that the notices sent out to Americans actually tell them what their mistake was and how long they have to appeal it. (It’s Recommendation #9 on this year’s list.) The IRS MATH Act, signed by Trump last week, is Congress finally taking her up on it.

Under the measure, the IRS math error notices will have to describe the “mathematical or clerical error” a taxpayer made “in comprehensive, plain language,” including by explaining to them “the nature of the error” and pointing them to “the specific line of the return on which the error was made.”

The IRS will also have to give an “itemized computation” of how the correction will change their adjusted gross income, taxable income, deduction amount, or tax credits.