LLC Operating Agreement Requirements in Michigan

At a glance

Requirements one by one

Michigan recognizes a written operating agreement only

MCL § 450.4102(2)(r) defines the document as a written agreement made by the sole member or between all members. An oral understanding or an arrangement implied only from conduct therefore does not qualify as the Act's operating agreement. The LLC Act adds no general witness, acknowledgment, or notarization condition.

The agreement is optional. Under § 450.4202(2), the articles' effective date begins the LLC's existence. Until the members adopt a qualifying agreement, the Act's management, voting, distribution, admission, and transfer defaults control.

Formation admission does not always require an agreement signature

Section 450.4501 distinguishes the agreement's required written form from one person's proof of initial membership. If the agreement has no admission rule, an initial member can qualify by signing it, but the statute also recognizes membership reflected in company records, tax filings, or another written company statement (§ 450.4501(1)).

A later direct admission follows the operating agreement's procedure. If the agreement supplies none, every voting member must approve. Michigan does not state a general rule deeming every later-admitted member to have assented to every existing term.

The articles choose member or manager management

Under § 450.4401, management defaults to the members unless the articles state that one or more managers will manage the business. In the default structure, members are treated as managers for the Act's agency, duty, liability, and indemnification rules. If there are multiple managers, § 450.4405 gives each one a vote and uses a majority of all managers for matters within their authority.

Authority to outsiders is not only an internal drafting question. Section 450.4406 makes a manager an agent for the LLC's business. In a manager-managed company, the articles also give third parties notice that managers rather than members hold that statutory agency authority.

Equal votes and equal distributions are the modern defaults

For an LLC formed on or after July 1, 1997, § 450.4502(1) gives each member one vote when the agreement does not allocate voting differently. A majority in interest generally decides a matter submitted to members; because the default is one vote per member, this is not automatically a capital-percentage test. The term "majority in interest" means the majority of votes allocated under the agreement or the statutory default (§ 450.4102(2)(n)).

Section 450.4303(1) likewise uses equal distribution shares for post-1997 LLCs unless the agreement provides another allocation. Example: if two members contributed different amounts but adopted no distribution clause, the statutory default is equal shares, not contribution-ratio shares (§ 450.4303(1)).

An assignment does not transfer governance by itself. Under §§ 450.4505-.4506, the assignee does not become a member or receive management rights merely by receiving the interest; absent a different agreement rule, admitting that assignee as a member requires unanimous approval.

Michigan states duties and liability limits section by section

Michigan has no single statutory list saying every provision an operating agreement may never change. Section 450.4404(1) imposes good-faith, prudent-care, and company-interest duties on managers, but its profit-accounting rule expressly yields to an operating agreement or the stated member vote (§ 450.4404(1)). Section 450.4407 permits an agreement or the articles to limit monetary liability for a duty breach while preserving the exceptions listed in that section.

Other statutory remedies still need separate attention. Section 450.4308 imposes liability for an unlawful distribution under its conditions. Section 450.4515 authorizes a member action over illegal, fraudulent, or willfully unfair and oppressive conduct, and § 450.4802 permits judicial dissolution when the company cannot operate in conformity with its articles or agreements (§ 450.4308(1); § 450.4515(1)).

The agreement is private, but the articles win a conflict

The operating agreement is not the document filed to create the company; the articles are. If the two conflict, § 450.4214 says the articles control. The Act does not state a separate default amendment procedure, while its definition continues to describe the agreement as a writing by the sole member or between all members.

Section 450.4213 requires records that let a member determine relative distribution shares and voting rights (§ 450.4213(f)). Section 450.4503 separately preserves a formal accounting when the agreement provides one or circumstances make it just and reasonable (§ 450.4503(5)).

What trips people up

Written does not always mean every initial member must sign. The agreement itself must be written, but § 450.4501 recognizes an initial membership shown in company records, tax filings, or another written company statement when the agreement has no admission rule.

Percentage ownership is not the statutory voting default. For a modern Michigan LLC, the default is one vote per member. A percentage-interest voting clause is a negotiated replacement.

The private agreement cannot override conflicting articles. Section 450.4214 gives the filed articles priority when the two documents say different things.

Common questions

Can a Michigan LLC rely on an oral operating agreement?

No. MCL 450.4102(2)(r) defines the statutory operating agreement as a written agreement.

Does a sole-member Michigan LLC need a second party?

No. Section 450.4215 says the agreement is not unenforceable merely because one person is its only party.

Does transferring an interest make the buyer a voting member?

Not by itself. The assignment transfers the interest subject to the agreement, but § 450.4505 says it does not automatically confer member or management rights.

Statutes and sources

• MCL 450.4102, 450.4202, 450.4213-.4215 — definition, written form, formation, records, article priority, and sole-member enforceability. Official Michigan Legislature section pages (accessed 2026-07-26).
• MCL 450.4303, 450.4308, 450.4401, 450.4404-.4407 — distributions, unlawful- distribution liability, management, authority, duties, and liability limits. Official Michigan Legislature section pages (accessed 2026-07-26).
• MCL 450.4501-.4506, 450.4515, 450.4802 — admission, voting, accounting, assignments, assignee admission, member remedies, and judicial dissolution. Official Michigan Legislature section pages (accessed 2026-07-26).