Michigan: LLC Operating Agreement Requirements
The short answer
Michigan does not require a domestic LLC to adopt an operating agreement, but any agreement that qualifies under the Michigan Limited Liability Company Act must be written. A sole member may make one, while a multi-member agreement is between all members; if no valid agreement changes the defaults, the Act supplies member-management, one-vote-per-member, equal-distribution, admission, transfer, duty, and records rules.
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This is the general rule in Michigan. Ezel applies current Michigan law to your specific facts and answers with citations to the statutes.
| Governing law and document name | Michigan Limited Liability Company Act; 'operating agreement' (MCL 450.4101, 450.4102(2)(r)) |
|---|---|
| Required or optional | Optional; the LLC exists when the articles become effective, while the Act's defaults apply without an agreement (MCL 450.4202(2)) |
| Permitted form and signatures | Written agreement only; sole member or all members. No general witness, acknowledgment, or notary rule; an initial member need not sign if status is shown in company records, tax filings, or another written statement (MCL 450.4102(2)(r), 450.4501(1)) |
| Adoption timing and effect | May govern admission in connection with formation or after formation; no general adoption deadline. The LLC itself begins only when the articles become effective (MCL 450.4202(2), 450.4501(1)-(2)) |
| Single member and assent | Sole-member agreement expressly enforceable. No general later-member deemed-assent rule; postformation admission follows the agreement or, absent a rule, unanimous member vote (MCL 450.4215, 450.4501(2)) |
| Management and authority defaults | Member-managed unless the articles delegate management to managers; members then count as managers. Multiple managers decide by majority, and a manager is the LLC's business agent (MCL 450.4401-.4406) |
| Voting, economic, and transfer defaults | For post-1997 LLCs, 1 vote and equal distributions per member; majority in interest generally decides submitted matters. New members and assignee admission require unanimity absent agreement; assignment alone carries no member-management rights (MCL 450.4303, 450.4501-.4506) |
| Nonwaivable rules and duties | No general nonwaivable-term list. Managers owe statutory good-faith, prudent-care, and company-interest duties; an agreement may alter the profit-accounting duty and limit monetary liability, but § 450.4407 preserves stated exceptions. Distribution liability, member court remedies, and judicial dissolution remain statutory (MCL 450.4308, 450.4404, 450.4407, 450.4515, 450.4802) |
| Amendment, filing, and records | No separate statutory amendment method; the defined agreement is written and made by the sole member or all members. It is not the formation filing; articles control conflicts. Keep records showing distribution and voting shares, and formal accounting remains available as the agreement provides or when just and reasonable (MCL 450.4102(2)(r), 450.4213(f)-.4214, 450.4503(5)) |
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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).
Source links
Every statute quoted above, linked, with the date we checked it.
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