When facing an audit, one is guilt until they prove their innocence. Moreover most taxpayers are so afraid of the IRS that they never challenge the exhortation assessment made in the audit. This is why you need a representative who knows whether the auditor is being fair and reasonable or needs to be challenged.
Taxpayers often seek to retain our firm after an audit assessment. While we can often provide value, it is often much more difficult to achieve a fair and accurate assessment of tax owed. Those taxpayers who seek competent representation prior to the audit often have a better chance of reducing the assessment or in minimizing penalties.