The Cohan rule is named for George Cohan, a brilliant actor, playwright, and producer, and also an inspiration to thousands of taxpayers who had lousy tax records. He claimed a variety of business expenses and had little evidence to support them, but could prove that he actually incurred the expenses.

For years, the courts applied the Cohan rule to estimate deductions for taxpayers who arrived in court with lousy records. To make sure that taxpayers felt pain for their failures, ... Log in to view full article.