When an Illinois CPA firm needs a firm license
Which Illinois CPA practices need a separate public accounting firm license, the peer review requirement, and how to check a firm.
Checked against sources on Oct 21, 2026
Who needs a firm license
According to the Illinois CPA Society, partnerships, LLPs, LLCs and other entities that hold themselves out as CPA firms, or that perform audits, reviews of historical financial statements or examinations of prospective financial information, must hold a separate public accounting firm license before issuing the report. A sole practitioner needs only an individual license unless the firm name suggests more than one person, such as “and associates” or “and company”.
Peer review
Firms and sole practitioners performing those services must enroll in an approved peer review program and satisfactorily complete a peer review for license and renewal purposes, according to the Illinois CPA Society.
In the data
IDFPR’s data checked Oct 21, 2026 has 945 current public accounting firm licenses with an Illinois address. Firm license numbers start with 066 and current ones expire November 30, 2027. Check a firm.
Questions
Does a sole-practitioner CPA need a firm license in Illinois?
Only if the firm name suggests more than one person, such as 'and associates', or as otherwise required for licensed services, according to the Illinois CPA Society.
What does an Illinois CPA firm license number look like?
Nine digits starting with 066, in the IDFPR data.