The Operating Agreement is the primary document that proves membership in an Arizona LLC. A properly drafted Operating Agreement identifies each member by name, states each member's ownership percentage or membership interest, and is signed by all members. Courts, banks, title companies, and other third parties treat the Operating Agreement as the definitive evidence of who owns the LLC and in what proportions.

If the LLC was formed by KEYTLaw, your Operating Agreement was custom-drafted to clearly name you as a member and state your ownership percentage from day one.

Arizona LLC law requires all members of a member-managed LLC to be named in the LLC's Articles of Organization. The law also requires all members of a manager-managed LLC who own 20% or more of the LLC to be named in the Articles of Organization.

Unfortunately many Articles of Organization fail to name any or all of the members.

If the LLC has no written Operating Agreement, membership must be proved through other evidence. This can include emails, text messages, wire transfer records showing capital contributions, bank statements, meeting minutes, or witness testimony. This situation creates significant legal risk and uncertainty, because these types of evidence are far weaker than a properly signed Operating Agreement and are far easier to dispute.

Without a written Operating Agreement, a member may find it impossible to satisfy a bank's due diligence requirements, a title company's documentation requirements, or a court's evidentiary standards. Every Arizona LLC should have a written Operating Agreement signed by all members.

Yes, a membership certificate can serve as evidence of membership, but only if it is properly issued under the LLC's Operating Agreement. Unlike stock certificates in a corporation, Arizona law does not require LLCs to issue membership certificates. If the Operating Agreement authorizes them and a certificate is properly issued and signed, it can be strong secondary evidence of membership.

However, a membership certificate is not a substitute for a written Operating Agreement. The Operating Agreement remains the primary legal document. A membership certificate without a supporting Operating Agreement carries much less weight.

Banks typically require a copy of the LLC's Operating Agreement that identifies the member and states the member's ownership interest. Most banks also require:

• The Articles of Organization to confirm the LLC's legal existence and name
• A certificate of good standing from the Arizona Corporation Commission showing the LLC is currently in good standing
• Government-issued identification for the member or authorized signatory
• The LLC's federal Employer Identification Number (EIN)

The Operating Agreement is the centerpiece of this package because it is the only document that identifies who the members are and what authority each member has.

In a real estate transaction, the title company will conduct its own due diligence before insuring the transaction. The title company typically requires:

• The LLC's Operating Agreement (with all amendments)
• The Articles of Organization
• A certificate of good standing from the Arizona Corporation Commission
• Written evidence that the member or manager signing the deed or contract has authority to bind the LLC

The title company reviews these documents to confirm the LLC exists, that the person acting on behalf of the LLC is actually a member or authorized manager, and that the LLC has the authority to buy or sell real estate.

When a new member is admitted to an existing LLC, the members should execute a written amendment to the Operating Agreement — or a Membership Interest Assignment Agreement — that identifies the new member, states the new member's ownership interest, and is signed by the existing members and the new member.

This written amendment to the Operating Agreement is the primary proof of the new member's membership going forward. Without it, the new member will have great difficulty proving membership to banks, title companies, courts, and other third parties, even if everyone involved understands informally that a new member was admitted.

A capital contribution alone does not prove membership. Under Arizona law, membership is created by agreement — not merely by the payment of money. A person can lend money to an LLC, pay for services rendered to the LLC, or make a payment for any number of reasons without becoming a member.

However, records of a capital contribution — such as a wire transfer receipt, cancelled check, or bank statement — can serve as strong supporting evidence of membership when combined with an Operating Agreement or other written agreement that expressly grants membership in exchange for that contribution. The combination of a written agreement and financial records is far more persuasive than either alone.

Tax returns can serve as supporting evidence of LLC membership. For example:

• A Schedule K-1 issued to a member from a partnership-taxed multi-member LLC shows that the IRS treated that person as a member for tax purposes.
• A single-member LLC owner who reports the LLC's income and expenses on Schedule C of their personal Form 1040 is demonstrating that they treated themselves as the sole owner for federal income tax purposes.
• The LLC's own tax return (Form 1065 for a partnership-taxed LLC) will list the members on the Schedule K-1 attachments.

While tax returns are not definitive legal proof of membership — because the IRS is not the authority on LLC ownership — they provide strong corroborating evidence that the person was treated as a member by the LLC and by the IRS.

The best proof for a single-member LLC is a written Operating Agreement that clearly states:

• The single member's full legal name (or entity name if the member is a trust, corporation, or other LLC)
• That the member owns 100% of the membership interests
• The member's capital contribution
• Whether the LLC is member-managed (the most common structure for single-member LLCs)

Even though Arizona law does not require an Operating Agreement, having one is critical for proving membership to banks, title companies, lenders, courts, and other third parties. Without a written Operating Agreement, a single-member LLC owner may struggle to prove ownership in disputes or transactions and may find that important third parties refuse to do business with the LLC.

Arizona LLC membership is governed primarily by the Arizona Limited Liability Company Act, found at Arizona Revised Statutes Title 29, Chapter 7 (A.R.S. §§ 29-3101 et seq.), which became effective September 1, 2019. This Act replaced the prior Arizona LLC statute and significantly modernized Arizona LLC law.

Under A.R.S. § 29-3401, a person becomes a member of an LLC at the time and on the terms stated in the Operating Agreement, or if the Operating Agreement does not provide a time, when the LLC's records reflect the admission. This statutory language reinforces that the Operating Agreement and the LLC's internal records are the controlling legal authorities on membership.

Yes. An experienced Arizona LLC attorney can draft an Operating Agreement that clearly identifies all members, states each member's ownership interest, and includes the provisions required to satisfy banks, title companies, lenders, and courts. A properly drafted Operating Agreement also addresses what happens when a member dies, becomes incapacitated, or wants to transfer a membership interest — all situations where proving membership becomes critical.

Online legal services and do-it-yourself Operating Agreement templates often omit provisions that are essential under Arizona's specific LLC laws and fail to address real-world scenarios that require proof of membership. Paying for a properly drafted Operating Agreement at the time of formation is far less expensive than trying to fix membership disputes or documentation gaps after they arise.

KEYTLaw's Arizona LLC formation packages include a custom Operating Agreement prepared by Arizona LLC attorney Richard Keyt, who has formed more than 10,000 Arizona LLCs since 1979. To hire KEYTLaw attorneys to prepare an Operating Agreement for your Arizona LLC submit our Operating Agreement questionnaire at https://azllc.com/oaq/.