LLC Operating Agreement Requirements in Illinois

At a glance

Requirements one by one

Governing law and document name

The Illinois Limited Liability Company Act uses operating agreement for the members' agreement about their relations with each other, managers, and the LLC. Section 1-5 makes the label noncontrolling: an arrangement can meet the definition “whether or not referred to as an operating agreement.”

Required or optional

Illinois uses permissive language. Section 15-5(a) says all members “may enter into” an operating agreement and then supplies the consequence of silence: to the extent the agreement does not provide otherwise, the Act governs the relations among members, managers, and the company.

Permitted form and signatures

The § 1-5 definition recognizes oral, record-form, implied, and combined agreements, including an agreement of a sole member. The LLC Act adds no general signature, witness, acknowledgment, or notarization condition to that definition. A separate law can still require a signed or recorded document for a particular promise, asset, or transaction.

Adoption timing and effect

Section 15-5(h) permits the agreement to be entered before, at, or after filing the articles of organization. It may take effect when the LLC forms or at another time or date stated in the agreement. Section 5-5(b) separately fixes when the company itself is organized, so a stated effective date does not make an Illinois LLC exist before its formation filing takes effect.

Single member and assent

Section 1-5 expressly includes a sole member in the agreement definition. Section 15-5(f) binds the LLC even without a separate manifestation of assent, and subsection (g) deems a person who becomes a member to assent. Section 10-1(a)(1) also recognizes the organizer's agreement with the one initial member as the route to initial membership at formation.

Management and authority defaults

Under § 15-1(a), an Illinois LLC is member-managed unless the operating agreement expressly makes it manager-managed or uses similar language. Members have equal management rights, and a majority of members decides ordinary company business. Manager-managed status shifts those ordinary decisions to the manager or a majority of managers.

Internal management power and third-party agency are different questions. Section 13-5 says member status alone does not make a person the company's agent. Under § 13-15, a filed statement of authority can conclusively protect a value-giving outsider who relies on a qualifying grant, and a properly recorded real-property limitation can charge outsiders with knowledge.

Voting, economic, and transfer defaults

The ordinary management baseline is one equal right per member, not voting by contribution or percentage interest (§ 15-1(b)). The same section reserves listed decisions for every member, including amendment of the agreement, admission of a new member, and disposal of substantially all company property. Section 25-1 makes interim distributions equal shares unless a valid agreement changes that default.

Transfer does not carry the whole membership package. Sections 30-1 and 30-5 allow transfer of the distributional interest but give the transferee only the transferred distributions. Under § 30-10, management, information, and member rights follow only if the operating agreement authorizes admission or all other members consent; § 10-1 states the same all-member fallback for admission.

Nonwaivable rules and duties

Section 15-3 states loyalty and care duties without limiting duties owed at common law, and applies the implied contractual covenant of good faith and fair dealing. Section 15-5 allows clear and unambiguous fiduciary modifications within stated limits, but it does not permit the agreement to authorize intentional misconduct or a knowing violation of law. It also protects reasonable access to information under §§ 1-40 and 10-15, the power to dissociate, statement-of-authority priority, rights of specified nonparties, the good-faith covenant, and liability for listed misconduct and improper benefits. The liability exceptions in § 15-5(e) remain.

Amendment, filing, and records

The statutory default is unanimous amendment under § 15-1(d)(1). The operating agreement itself is not a mandatory articles filing; § 5-5(a)(8) instead lets members elect to place compatible internal provisions in the articles.

If the agreement is written, § 1-40(a)(4) requires the LLC to retain the effective agreement and amendments at its principal place of business or another reasonable location specified in the agreement. Members may inspect and copy the retained records during ordinary business hours, and §§ 1-40 and 10-15 provide court enforcement for denied access.

What trips people up

• Equal management rights are a per-member default. The live template's percentage-interest voting clause is a drafting choice; § 15-1(b) instead starts with equal management rights and a majority of members for ordinary business.
• The private agreement does not by itself announce authority to outsiders. Section 13-5 rejects automatic agency based only on membership, while § 13-15 gives separate consequences to a filed statement of authority and, for real property, its recording.
• A transfer of distributions is not admission as a member. Sections 30-5 and 30-10 separate the economic transfer from management, information, and voting rights.

Common questions

Can an Illinois operating agreement be electronic? Yes. Section 1-5 defines a “record” as information stored on a tangible, electronic, or other medium that can be retrieved in perceivable form, and recognizes an operating agreement in a record.

Can one member force an amendment under the statutory default? No. Section 15-1(d)(1) requires all members to consent to an operating-agreement amendment unless the agreement validly supplies another rule.

Must a transferee receive company information? Not as a member merely because of the transfer. Section 30-10(d) denies ordinary management and information rights to a nonmember transferee, although § 1-40(c)–(d) supplies a narrower records route for a proper purpose.

Statutes and sources

• 805 ILCS 180/1-5 and 1-40 — agreement definition, recognized forms, sole-member coverage, retained written agreements, and inspection rights. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K1-5.htm and https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K1-40.htm (accessed 2026-07-26)
• 805 ILCS 180/5-5 and 10-1 — formation time, optional articles provisions, and initial or later member admission. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K5-5.htm and https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K10-1.htm (accessed 2026-07-26)
• 805 ILCS 180/10-15 — member and dissociated-member information rights, reasonable restrictions, and court enforcement. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K10-15.htm (accessed 2026-07-26)
• 805 ILCS 180/13-5 and 13-15 — no automatic member agency and filed statements of authority. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K13-5.htm and https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K13-15.htm (accessed 2026-07-26)
• 805 ILCS 180/15-1, 15-3, and 15-5 — management, voting, unanimous matters, duties, agreement scope and timing, assent, and nonwaivable limits. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K15-1.htm, https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K15-3.htm, https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K15-5.htm (accessed 2026-07-26)
• 805 ILCS 180/25-1 and 30-1, 30-5, 30-10 — equal interim distributions and the separation of economic transfers from membership and governance rights. https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K25-1.htm, https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K30-1.htm, https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K30-5.htm, and https://www.ilga.gov/documents/legislation/ilcs/documents/080501800K30-10.htm (accessed 2026-07-26)