Like it or not, the IRS exists to enforce compliance and collect tax. While its employees are generally good professional individuals, they are still human, make mistakes, and as in other aspects of life, reasonable people can come to differing conclusions. When those instances happen, you want an experienced taxpayer representative on your side to defend your instances and your rights.
Tax Audits: The IRS has several different types of audits that it conducts. The most common is from the Automated Underreporter Unit (AUR) which is consists of computer generated notices that match up discrepancies between the filed tax return and income information it receives from third parties via filed 1099s and W-2s.
Another form of audit is the correspondence audit. Like the audit from AUR, this one is conducted via mail, however an actual examiner will be reviewing the audit and it involves providing documentation to support specific items reported on the return rather than possible missing items.
Live audits involve both Revenue Agents and Tax Compliance Officers, who will visit your business or have you go to a local IRS office to conduct your audit. It is in your best interest to have a representative to protect your interests and argue your case if items are not readily accepted by the examiner.
Collections: When the IRS has assessed tax and you have not or cannot pay (whether you agree with the tax or not), the unpaid liability is sent to their collections unit. The job of Revenue Officers is to collect tax and make taxpayers current on all un-filed returns. Collections has a wide variety of tools at its disposal to collect tax including but not limited to: wage garnishments, bank levies, Notice of Federal Tax Lien (NTFL), and property seizure. While the IRS has the ability to enforce collections, there are also internal procedures and fair debt collections laws they must adhere to. An experienced Enrolled Agent can protect your interests and work with the IRS to move in less disruptive collection practices.
Appeals: Some times you believe in the correctness of your position, but you can't come to an agreement with an examiner. Appeals is an independent division of the IRS that looks to resolve disagreements based on the hazards of litigation. Many times an agreement can be reached if not an outright finding on behalf of the taxpayer. Since appeals operates independently, they look at the case objectively. The agents are also more experienced and better versed in the law. It is in the taxpayer's best interest to have a representative who is also well versed in the law and able to argue persuasively on their behalf.