Form IL-2848 is the Illinois Power of Attorney: the document that authorizes a representative to deal with the Illinois Department of Revenue on your behalf. If you have ever hired help for an IRS problem, you know the federal version, Form 2848. The catch that surprises people is that the federal form does nothing for your Illinois account. The two systems each require their own authorization.
What the IL-2848 lets a representative do
With a valid IL-2848 on file, your representative can communicate with IDOR about your account, receive your notices and account information, and negotiate on your behalf: payment arrangements, disputes, levy releases, and the rest of the resolution toolkit. Without it, Illinois will not discuss your account with anyone but you, no matter how qualified the person calling is.
Why both forms matter in a real case
Most serious tax problems are federal and state at once. The IRS adjusts a return, Illinois recalculates to match, and suddenly there are two agencies, two balances, and two sets of deadlines. Representation that covers only the federal side leaves the Illinois half unattended, which is how state levies arrive mid-way through an IRS negotiation. When we take on a case with an Illinois component, both authorizations go on file at the start, so nothing about either account moves without us seeing it.
Completing it right
The form asks who you are, who represents you, which taxes and periods are covered, and your signature authorizing it. The common failure is scope: an authorization covering the wrong tax type or the wrong years is a form IDOR will honor precisely and uselessly. List the periods the problem actually spans, include the current year where ongoing filings matter, and keep a copy. Your representative handles the filing; what you should understand is what you signed and how to revoke it, which you can do at any time in writing.