- the procedures you used to figure your tax base,
- any exemptions and deductions you claimed, and
- the overall accuracy of tax returns you filed.
The methods and procedures used in an audit will vary because of the different tax types and business categories that exist. For example, the methods used in a sales tax audit for a flower shop would be different from the methods used in a sales tax audit of a manufacturer. Even though both businesses may be undergoing a sales tax audit, the way of doing business is different for both businesses; therefore, the methods of reviewing the records of the business will be different.
In general, sales and excise tax auditing methods and procedures will include testing and detailed reviews of source documents and general ledger accounts. Similarly, income tax auditing methods and procedures include detailed reviews of federal or consolidated returns and associated schedules, in comparison to the returns and schedules filed for Illinois purposes.