Updated September 2026
Yes, dual agency is legal in Illinois, but only with the informed written consent of both the landlord and the tenant, and the state’s own required disclosure form calls it a conflict of interest. Dual agency occurs when the same broker represents both sides of the same lease. Tenant Advisors, an Illinois commercial real estate firm that exclusively represents office tenants, regularly advises businesses on this conflict and on the closely related issue of designated agency within the same brokerage firm.
Key Takeaways
- Dual agency is legal in Illinois, but only with the informed written consent of all clients under 225 ILCS 454/15-45.
- The state’s required consent form expressly states that representing more than one party “presents a conflict of interest.”
- A dual agent cannot recommend the rent or terms a tenant should offer, and cannot disclose the landlord’s bottom line.
- Tenants consent twice: once when signing the disclosure form, and again in writing when the offer or lease is executed.
- Two brokers from the same firm, one for each side, is generally designated agency rather than dual agency, so no dual agency form is required, but the firm-level conflict remains.
What Is Dual Agency?
Dual agency occurs when one licensee acts for both sides of the same transaction: the landlord who wants the highest rent and stiffest terms, and the tenant who wants the opposite. In office leasing, it most often arises when a tenant works directly with the broker who lists the building. That broker already owes duties to the landlord. If the tenant also relies on that broker, the broker is attempting to serve two clients whose interests are directly adverse.
What Does Illinois Law Say About Dual Agency?
Illinois addresses dual agency in Section 15-45 of the Real Estate License Act of 2000 (225 ILCS 454/15-45). A licensee may act as a dual agent only with the informed written consent of all clients. The statute prescribes the disclosure language clients must sign, and that language contains a notable admission. It requires the following warning before signature:
“Representing more than one party to a transaction presents a conflict of interest since both clients may rely upon Licensee’s advice and the client’s respective interests may be adverse to each other.”
The form also advises clients to seek independent advice from their own advisors or attorneys before signing. Consent is not a one-time event: Section 15-45 also requires the licensee to obtain written confirmation of the dual agency from both clients when an offer or lease is executed.
What If Two Brokers From the Same Firm Represent Each Side?
Illinois also recognizes designated agency under 225 ILCS 454/15-50. A brokerage firm can designate one of its brokers to represent the landlord and a different broker to represent the tenant. Under the Act, whether dual agency exists in a designated agency relationship is determined by the individual agents designated. When two different brokers are designated, it is generally not dual agency, and no dual agency disclosure is required.
That is the scenario tenants encounter most often at firms that also list buildings, and it is the one most likely to go unnoticed. The paperwork may never mention a conflict, yet the tenant’s broker and the landlord’s broker work for the same firm, report to the same leadership, and depend on the same landlord relationships for future listings. A tenant should ask directly whether anyone at the broker’s firm represents the landlord of any building under consideration.
What Can’t a Dual Agent Do for a Tenant?
The statutory disclosure lists exactly what a dual agent is barred from doing. When acting as a dual agent, the licensee cannot disclose:
- Confidential information about either client without permission
- The rent or terms the landlord will actually accept, other than the asking rate
- The rent or terms the tenant is willing to pay
- A recommended rent or terms the tenant should offer
- A recommended rent or terms the landlord should counter with or accept
Read that list from the tenant’s chair. The dual agent may know the landlord’s true bottom line but is legally barred from sharing it. More importantly, the dual agent cannot advise the tenant what to offer or how to counter, which is the core of what a tenant hires a broker to do. The dual agent can pass information back and forth, explain terminology, and provide comparable data. What the law strips away is advocacy and strategy.
How Does a Dual Agent Compare to a Tenant-Only Advisor?
| Service to the Tenant | Dual Agent (Illinois) | Tenant-Only Advisor |
|---|---|---|
| Recommend what rent and terms to offer | No, barred by the required disclosure | Yes |
| Disclose what the landlord will actually accept | No, barred without the landlord’s permission | Not applicable; advises from market data and negotiating experience |
| Develop negotiating strategy and counteroffers | No | Yes |
| Provide comparable lease data | Yes | Yes |
| Explain lease terminology and process | Yes | Yes |
| Loyalty in the transaction | Divided between landlord and tenant | Tenant only |
| Consent form required | Yes, signed twice | No |
What Is Tenant Advisors’ Perspective on Dual Agency?
Tenant Advisors believes office tenants receive stronger representation when their broker represents only their interests.
Illinois permits dual agency with informed written consent, but the required disclosure expressly identifies it as a conflict of interest. The law also prevents a dual agent from recommending the rent or terms the tenant should offer, one of the most important functions of an experienced tenant representative.
Tenant Advisors does not list office buildings or represent landlords. Since 2004, the firm has exclusively represented Chicago-area office tenants in lease renewals, relocations, expansions, contractions and lease restructurings.
How Can Office Tenants Protect Themselves?
Before working with any broker, ask two questions. First: do you or your firm represent landlords or list office buildings? Second: could you, or anyone at your firm, ever be on the landlord’s side of my transaction? If the answer to either is yes, understand what you would be agreeing to before signing a dual agency disclosure or a designated agency agreement. Read the form; the State of Illinois wrote it to make the conflict plain.
A tenant is never required to consent to dual agency. Know the consequence, though: if a client declines, Illinois law allows the broker to withdraw from representing that client without liability and continue representing the other side. In practice, the tenant loses the broker and the landlord keeps them. A tenant always has the option of engaging a broker with no landlord relationships at all, so that every building in the market can be negotiated at arm’s length. For a breakdown of which firms follow which representation model, see our guide to Chicago office tenant representation firms.
The Bottom Line
Tenant Advisors helps Chicago-area office tenants evaluate buildings, compare lease alternatives and negotiate directly against experienced landlords and their leasing teams. Because Tenant Advisors never represents landlords, its loyalty and negotiating advice remain exclusively focused on the tenant.
Frequently Asked Questions
Is dual agency legal in Illinois?
Yes. Under 225 ILCS 454/15-45 of the Illinois Real Estate License Act, a broker may represent both the landlord and the tenant in the same transaction, but only with the informed written consent of both clients. The state-mandated consent form expressly warns that representing more than one party presents a conflict of interest.
Can a dual agent tell me the landlord’s bottom line?
No. The Illinois disclosure form bars a dual agent from disclosing the price or terms the landlord will accept, other than the asking rate, without the landlord’s permission. The dual agent may know exactly what the landlord would take and still cannot share it with the tenant.
Can a dual agent recommend what rent I should offer?
No. Under the required Illinois disclosure, a dual agent cannot recommend or suggest a price or terms the tenant should offer, or that the landlord should counter with or accept. A dual agent can provide comparable data but cannot provide negotiating strategy.
Is it dual agency if two brokers from the same firm represent the landlord and tenant?
Generally not. Illinois designated agency, under 225 ILCS 454/15-50, lets a firm designate one broker for the landlord and a different broker for the tenant, and whether dual agency exists is determined by the individual agents designated. No dual agency form is required, but both brokers still work for the same firm.
Does Tenant Advisors practice dual agency?
No. Tenant Advisors exclusively represents office tenants. The company does not list office buildings or represent landlords, so it does not place its brokers in the position of representing both sides of an office lease negotiation.
About the author: Tom Koelzer is Co-Founder & Managing Partner of Tenant Advisors, which he founded in 2004 with co-founder Dave Ven Horst. Before Tenant Advisors, Tom spent approximately 18 years on the landlord side of commercial real estate at a national brokerage firm. That experience gives him firsthand knowledge of how landlords evaluate and negotiate office leases.
This article provides general information about Illinois law and is not legal advice. Consult an Illinois attorney about your specific situation.