To find out what type of LLC you have, pull four documents: your state Secretary of State’s business registry listing, your Articles of Organization, your Operating Agreement, and your IRS records for the LLC’s EIN. Together they tell you the four things that make up your LLC’s “type” — whether it’s member-managed or manager-managed, whether it’s single-member or multi-member, whether it carries a special designation like professional or series, and how the IRS classifies it for tax purposes. Most owners set the LLC up years ago and never revisited the paperwork, so the answers are usually sitting in a filing cabinet or a state database.
Start With Your State’s Business Registry
Every state maintains a Secretary of State business entity database, and most are free to search online. You can typically look up your LLC by business name, file number, or registered agent. The listing will show the official name, formation date, current status (active, inactive, or dissolved), registered agent, and in most states whether the LLC is member-managed or manager-managed. Some states also flag whether you formed a standard LLC, a professional LLC, or a series LLC.
This is the fastest way to confirm what your LLC looks like on paper, and it’s especially useful if you’ve lost your formation documents. Many states let you download a copy of your Articles of Organization straight from the database. If your LLC was formed in one state but you also registered it in another to do business there, you’ll appear in the second state’s registry as a “foreign” LLC. That label refers to another U.S. state, not another country.
Read Your Articles of Organization
Your Articles of Organization are the document you filed with the state to create the LLC. They spell out the legal name, principal address, registered agent, and whether the LLC is member-managed or manager-managed. Some states also require you to state the LLC’s purpose and duration. If you have a professional LLC or a series LLC, that designation almost always appears in the Articles, because most states require you to identify these special structures at formation. If the Articles don’t mention “series,” you don’t have a series LLC. If they don’t identify the entity as a PLLC, you have a standard LLC.
Check Your Operating Agreement
Your Operating Agreement fills in what the Articles leave out. It covers who owns the LLC and in what percentages, how profits and losses are split, what decisions require a vote, and what happens when a member leaves or joins. In a manager-managed LLC, the Operating Agreement usually spells out exactly what the managers can do on their own — signing contracts, opening bank accounts, borrowing money — and which decisions still need member approval. Not every state requires an Operating Agreement, but if you have one, it’s the single clearest statement of how you intended to run the company.
Member-Managed or Manager-Managed
Every LLC falls into one of two management categories. In a member-managed LLC, every owner participates in daily operations and can make binding decisions for the company. In a manager-managed LLC, one or more designated managers run the business while the other members stay passive, closer to investors in a corporation.
To find out which yours is, check the Articles of Organization first. Most states require you to declare the structure there. If the Articles are silent, check the Operating Agreement. If neither document addresses management, your state’s default LLC statute controls, and the default in most states is member-managed.
The distinction matters when someone asks whose signature binds the company. In a member-managed LLC, any member can sign a lease, hire an employee, or commit the company to a contract. In a manager-managed LLC, only the designated managers can. Banks and vendors will often ask which structure you use before extending credit or opening accounts.
Single-Member or Multi-Member
Count your owners. A single-member LLC has one; a multi-member LLC has two or more. This drives the default tax treatment and shapes a few legal risks.
The IRS treats a single-member LLC as a “disregarded entity.” The LLC itself doesn’t file a separate federal income tax return; you report the business’s income and expenses on your personal return, usually on Schedule C of Form 1040.1Internal Revenue Service. Single Member Limited Liability Companies Single-member LLCs are also the most exposed to what courts call “piercing the veil” — a ruling that your liability protection doesn’t apply because you treated the company and yourself as the same person. The most common trigger is commingling funds: paying personal bills from the business account, depositing business checks into your personal account, or failing to keep separate books. If a court finds you and the LLC indistinguishable, creditors can reach your personal assets.
The IRS defaults to treating a multi-member LLC as a partnership. The LLC files an informational return on Form 1065 and issues each member a Schedule K-1 showing their share of income, deductions, and credits.2Internal Revenue Service. LLC Filing as a Corporation or Partnership The LLC itself doesn’t pay federal income tax; each member reports their share on their own return.3Internal Revenue Service. About Form 1065, U.S. Return of Partnership Income
Whether You Have a Professional or Series LLC
Two special LLC types exist, and your Articles of Organization will tell you if either applies to you.
A Professional LLC, usually abbreviated PLLC, is reserved for people who hold state-issued professional licenses — physicians, attorneys, accountants, engineers, architects, and similar practitioners. States that require the PLLC form typically won’t let a licensed professional operate through a standard LLC. Formation usually involves approval from the relevant licensing board alongside the Secretary of State filing, and the Articles of Organization will identify the entity as a PLLC and often list the specific licensed services it’s authorized to provide. A PLLC shields members from each other’s general business debts but does not protect a professional from liability for their own malpractice.
A Series LLC is a single LLC that contains multiple internal divisions called “series,” each with its own assets, liabilities, and sometimes its own members. Real estate investors use the structure most often, placing each property in its own series so a claim against one theoretically can’t reach the others. Not every state authorizes series LLCs, and those that do require specific language in the Articles of Organization establishing the series structure. If the Articles don’t mention series, you don’t have one. Running a series LLC also requires strict recordkeeping — each series needs its own books, bank accounts, and contracts — because the separation is what the protection depends on.
Confirm Your Tax Classification With the IRS
Your LLC’s legal structure and its tax classification are two different things, and they don’t always match what you’d expect. An LLC can be taxed four ways: as a sole proprietorship (the single-member default), a partnership (the multi-member default), an S corporation, or a C corporation. The IRS assigned a default classification when you applied for your EIN, but you or a prior member may have changed it.
The quickest way to confirm your current classification is to find your IRS CP 575 notice, the letter the IRS sent when it issued your EIN. It states the classification the IRS has on file. If you’ve lost the letter, call the IRS Business and Specialty Tax Line and ask for Letter 147C, which reconfirms your EIN and its current associated classification.4Internal Revenue Service. Employer Identification Number Keep in mind that a CP 575 reflects what was on file at formation. If anyone later filed Form 8832 (to elect corporate treatment) or Form 2553 (to elect S corporation status), the classification has changed since that notice was issued.
The Default Classifications
If no one has filed to change your treatment, the defaults apply. A single-member LLC is taxed as a sole proprietorship.1Internal Revenue Service. Single Member Limited Liability Companies A multi-member LLC is taxed as a partnership.2Internal Revenue Service. LLC Filing as a Corporation or Partnership Either way, income passes through to the owners and the LLC pays no federal income tax itself.
Signs Someone Elected a Different Classification
Look through your records for a filed Form 8832 or Form 2553, or for any IRS acceptance letter confirming an election. Old tax returns are also a clean giveaway: if your LLC has been filing Form 1120-S, it’s classified as an S corporation; Form 1120 means C corporation; Form 1065 means partnership; and Schedule C attached to a personal 1040 means sole proprietorship. A payroll history in your own name from the LLC is another sign of an S corporation election, since owners of default-taxed LLCs generally take draws rather than W-2 wages.
Why This Matters Before the Next Filing Deadline
Your classification sets your federal filing deadline, and partnership and S corporation returns are due a full month before personal returns. For calendar-year filers in 2026:
- Sole proprietorship (single-member default): reported on Form 1040, due April 15, 2026.
- Partnership (multi-member default): Form 1065 due March 15, 2026, with Schedule K-1s to members by the same date.5Internal Revenue Service. Publication 509 (2026), Tax Calendars
- S corporation: Form 1120-S due March 15, 2026, with Schedule K-1s to shareholders by the same date.5Internal Revenue Service. Publication 509 (2026), Tax Calendars
- C corporation: Form 1120 due April 15, 2026.
Late filing on a partnership or S corporation return triggers penalties that accrue per partner or shareholder per month. If you’re not sure which classification the IRS has on file for your LLC, requesting Letter 147C is the single most time-sensitive step on this list.