Most businesses normally keep only one set of books, usually maintained to present financial statements to stakeholders (shareholders, financial institutions or government regulators such as the IRS and SEC). Their CPAs, whether internal or from an outside firm make “tax adjustments” to convert “book income” to “taxable income” and then complete the appropriate forms notifying the IRS of the differences. However, if a business has two sets of books, the IRS becomes very skeptical very quickly.