This post was written as part of a series on tax excuses that don't work.

A popular lie about income taxes is that, quite simply, they aren't allowed by the U.S. Constitution. You'll hear tax protesters say, "Show me the place in the Constitution where it says I have to pay taxes!"

Well, they're sort of right. The Constitution itself doesn't give details on income taxes and who must pay them and how they must be paid. But the Constitution does give the U.S. government the right to create and enforce income tax laws in the Sixteenth Amendment.

Does your favorite tax protester take this argument even further by saying that the Sixteenth Amendment was not properly ratified so it doesn't count? Well he's wrong. It was, in fact, properly ratified and therefore must be followed. Income taxes are constitutional -- so says the U.S. Constitution.

Tracy L. Coenen, CPA, MBA, CFE performs fraud examinations and financial investigations for her company Sequence Inc. Forensic Accounting, and is the author of Essentials of Corporate Fraud.