IRS Audit Manual: IRS Audit Procedures

Preparation is the most important part of the audit. You will win or lose based on your preparation. Small errors should not concern you. Sometimes you have more deductions in a column than originally reported on the tax return. If other columns are short, it could be that you mixed receipts between the columns. This is also a common occurrence, especially between similar types of deductions. Supplies, office expense, and postage are similar enough to have some postage or supplies listed as an office expense.

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IRS Audit