To those unfamiliar with IRS procedures, everyone who works there might be called an “agent,” the same way that many taxpayers consider anyone who prepares tax returns a “CPA.” (People do that to me all the time.) So if you want to demonstrate your lack of familiarity with IRS job titles, call those who work there what you please. But if a revenue agent contacts your client, don’t refer to him/her as a customer service representative. And if you call and talk to a GS-4 temp at an IRS service center about a notice your client has received, don’t promote him/her to “agent,” at least when describing the contact to other tax professionals.
There are many websites that explain IRS job titles, and AI will offer suggestions also. Here is one that clears up the confusion about “revenue agents” and “revenue officers.”
https://www.bragertaxlaw.com/what-is-the-difference-between-an-irs-revenue-agent-and-a-revenu.html
“An IRS revenue agent's job is to conduct tax audits of individuals and businesses as well as trusts and non-profit organizations. Revenue agents generally conduct tax audits of the most complicated tax returns ranging from small "Schedule C" businesses to the largest multi-national corporations. . . .
The minimum requirement for a job as a revenue agent generally includes having a bachelor's degree or higher in accounting from an accredited college or university that included at least 30 semester hours in accounting. . . .Internal Revenue Agents are not required to be CPAs although a few are. . . .
Revenue Agents do not collect tax. Instead, that task falls to an IRS Revenue Officer or R.O. Revenue Officers are assigned to the most difficult IRS tax debt cases. Those individuals or businesses who the IRS has been unable to collect from through letters, phone calls and tax levies and garnishments generated by IRS computers. Revenue Officers are not generally accountants and they have little training in substantive law.”