IRS PUBLICATION 535 - BUSINESS EXPENSES

A document that explains common business expenses and gives guidance on what is and not deductible. Released by the Internal Revenue Service (IRS), it entails the general rules for deducting business expenses, and outlines the most common items taxpayers deduct. In order to be deductible, a business cost must be regarded as both ordinary and necessary.

"Ordinary" pertains to expenses that are common in a given industry while "necessary" refers to expenses that are helpful in operating a business. Cost of goods, personal, and capital expenses are different from business expenses, which means the deducting costs from receipts to determine profits precludes those expenses from also being deducted as a business expenditures. Capital expenses have to be capitalized rather than reduced.