Do I Need an Operating Agreement in Illinois?

No. Illinois law does not require an operating agreement for LLCs under 805 ILCS 180/15-5. However, without one, state default rules automatically govern your LLC's operations—including member management, equal profit splits, and statutory voting rights. Most business owners benefit from a written agreement to customize these terms and protect their interests.

What the Law Says

The Illinois Limited Liability Company Act permits LLCs to operate without a written operating agreement. If you don't create one, 805 ILCS 180/15-5 provides default rules covering member relations, management structure, and company governance. These defaults apply whether or not you have a formal agreement in place.

Default Rules That Apply Without an Agreement

If you skip an operating agreement, Illinois law automatically provides:

Member management. All members have equal management rights and authority.
Equal profit splits. Members share profits and losses equally, regardless of capital contributions.
Statutory voting rights. Members vote on major decisions according to state law.
Default transfer restrictions. Members cannot transfer membership interests without consent.

These rules may not match your actual business arrangement or ownership structure.

Why You Should Create One Anyway

An operating agreement lets you modify most Illinois LLC Act rules to fit your business. You can establish manager-management, customize profit distributions, define voting thresholds, set buyout procedures, and clarify member roles. A written agreement also prevents disputes by documenting each member's rights, obligations, and expectations upfront.

Banks, investors, and business partners often request operating agreements as proof of legitimate business structure. A well-drafted agreement also strengthens your liability protection by demonstrating you're treating the LLC as a separate entity.

What Happens When New Members Join

Under 805 ILCS 180/15-5, new members automatically assent to your existing operating agreement upon joining. This ensures consistent governance as your business grows—but only if you have a written agreement in place.

Next Steps

Decide on management structure. Determine whether your LLC will be member-managed or manager-managed.
Draft an operating agreement. Use a template, hire an attorney, or work with a business formation service.
Have all members sign. Ensure initial members execute the agreement.
Store it with your records. Keep the signed agreement accessible for reference and disputes.

The operating agreement doesn't need to be filed with the state—it's an internal document. However, maintaining a signed copy protects all parties if questions arise about member rights or company operations.

This is general information, not legal advice. Consult an Illinois business attorney for guidance specific to your situation.