Reasons and History Behind IRS's Recommendation to 'Discard' Cents (¢) and Report Only in Dollars

When preparing U.S. tax documents, you will often see the instruction "Round to the nearest dollar" next to almost every amount field.

I have summarized why amounts under one dollar are uniformly ignored (or rounded) and when this practice began.

IRC §6102 Introduced in 1954

The revised federal tax law (Internal Revenue Code) §6102, amended in 1954, states that the Secretary of the Treasury may determine that "if the amount shown on the tax return is not in dollars, ① all decimal places may be discarded, or ② amounts under 50 cents may be discarded and amounts of 50 cents or more may be rounded up to the nearest dollar." At the same time, taxpayers were also guaranteed the right to report amounts down to the cent if they wished.

Administrative Necessity: Early Computerization in the 1950s-60s

The mid-1950s, when the law was created, was a time when the IRS was entering tax returns using punch cards and early mainframes. Writing amounts in dollars only for one field reduced input errors and significantly saved processing speed and capacity. The 1955 Form 1040 instructions already included guidance to "record whole-dollar amounts if desired." This was the starting point for institutionalizing administrative convenience.

Current Guidelines: Most Forms Recommend Rounding

The 2024 Form 1040 instructions also state, "Round all amounts to the nearest dollar. Round down for amounts under 50 cents and round up for amounts of 50 cents or more." However, there are documents like the wage withholding report (Form 941) where exact cents are necessary, so those forms will still require cents to be reported as is.

• Reduced data entry and scanning errors and processing cost savings
• Convenience for taxpayers: reduced need to add or verify small cents individually
• Minimal practical impact on tax revenue: differences under 50 cents often offset across the return
• Maintaining choice: According to Treas. Reg. §301.6102-1, it is permissible to report cents in electronic filings, etc.
• If rounding is chosen, it must be applied consistently to all amounts on the same return.
• When summing multiple amounts, add up to the cent first, then round only the final total.

The practice of ignoring small cents began as a practical choice by the IRS in the 1950s to achieve both 'administrative efficiency + convenience' and has continued based on law. However, the law and regulations also leave the "freedom to report cents," so for necessary forms or industries (e.g., payroll reporting, financial institution 1099 issuance), amounts can still be reported down to two decimal places.