Guide

LLPs and series LLCs in Illinois: what they are

A regular LLC is the structure most Chicago resellers start with. Two other names come up: the limited liability partnership (LLP) and the series LLC. Here is what each one is, based on the Illinois statutes and what other sources say.

General information only, not legal or tax advice. I am not a lawyer, a CPA or an accountant. This page explains what public sources say. It does not tell you what your agreement should say. Agreements between owners should be reviewed by an Illinois attorney before anyone signs.

The short version

• A regular LLC separates the business from its owners. See what an LLC does and does not do.
• An LLP is a partnership that has chosen to limit its partners’ personal responsibility for the partnership’s obligations.
• A series LLC is one LLC that sets up separate “series” inside it, intended to keep the assets and debts of one series apart from the others.
• Both are more complicated than a regular LLC. Most new resellers do not need either, but you should know what they are, especially if a partner or an adviser mentions one.

Limited liability partnership (LLP)

A general partnership forms when two or more people run a for-profit business together (see operating agreements and joint ventures), and its partners are normally jointly and severally liable for its obligations. An LLP changes that.

Illinois’ partnership act says that an obligation of a partnership incurred while it is an LLP is solely the obligation of the partnership, and that a partner is not personally liable for it, directly or indirectly, solely because the person is a partner or acts as one. The statute also says this applies even if an earlier partnership agreement said otherwise. The statute refers to a partner vote to become an LLP (section 1001(b)). The filing rules are in the next section. The fees come from the Secretary of State’s forms page, saved Oct 30, 2026. Check them again before you file.

Points to keep in mind:

• The quoted protection is about the partnership’s obligations. It does not, by its text, say anything about debts you take on personally, such as a loan you guarantee, or about your own wrongful acts. Ask an attorney how it applies.
• An LLP is still a partnership. It still needs a partnership agreement covering ownership, decisions, money and exits, and it files a partnership tax return (see the IRS description in the partnership tax section).
• Some states and some professions have special LLP rules. Check the rules for your own situation.

Source: 805 ILCS 206/306, Illinois Compiled Statutes (opens in a new tab).

How an LLP is filed in Illinois

The Secretary of State’s own rules (14 Ill. Adm. Code Part 166, effective rules for LLPs under the Uniform Partnership Act) say the following. I read them in the official text.

• The form: A domestic LLP files Form UPA 1001, Limited Liability Partnership Statement of Qualification. Filings must be on the most recent version of the form the Secretary of State provides.
• Other forms: The same rules list forms for renewal (UPA 1003(D)), reinstatement (UPA 1004), amendments (UPA 1001(h)/1102(g)), withdrawal and for resigning as agent.
• The EIN: Every document filed for an LLP must include the LLP’s federal employer identification number. Plan to get the EIN first.
• The name: It cannot contain “Corporation,” “Corp.,” “Incorporated,” “Inc.,” “Company” or “Co.” It also cannot contain words that are offensive to good taste.
• Renewal: An LLP must be renewed. The renewal statement must be postmarked no later than the expiration date, with the fee. A timely renewal that needs fixes gets a 30-day extension.
• Paying: Fees for a statement of qualification are paid by money order, certified check, cashier’s check, a check from an Illinois attorney or CPA account, or by credit card, debit card or electronic funds transfer. A check that bounces voids the filing, and it is treated as never filed.
• Where: Paper filings go to the Department of Business Services in Springfield. Electronic filings must include the name of the person submitting them. That name counts as their statement, under penalty of perjury, that the facts are true.
• Fees: See the fee table below. The rules point to 805 ILCS 206/108 for fees. The amounts in the table come from the Secretary of State’s LLP forms page.

Source: 14 Ill. Adm. Code Part 166, Uniform Partnership Act (1997), Illinois General Assembly (opens in a new tab). Rules can change, so confirm with the Secretary of State and an attorney before filing.

LLP forms and fees

The Illinois Secretary of State lists these fees on its LLP publications and forms page. “Expedited” is the extra fee for faster processing. Cash is not accepted for filings with the Secretary of State.

Sources: Limited Liability Partnership Publications/Forms (opens in a new tab), Illinois Secretary of State (fees and forms; page saved Oct 30, 2026). Blank forms: UPA 1001 (PDF) (opens in a new tab), UPA 1003(D) (PDF) (opens in a new tab), UPA 1004 (PDF) (opens in a new tab). Fees can change, so confirm on the Secretary of State’s site before filing.

Partners in an LLP receive Schedule K-1s; see Schedule K-1 explained.

Series LLC

Illinois allows an LLC to create one or more series. The idea is that a series’ assets can be shielded from the debts of other series, so a company that owns several things (for example, several rental properties) can try to keep a problem with one from reaching the others. The Illinois LLC Act provision is section 37-40 (805 ILCS 180/37-40).

A law firm’s summary of a 2020 Illinois appellate case shows why the details matter. In City of Urbana v. Platinum Group Properties, LLC, a series claimed to be its own legal entity. The court said it did not prove it was properly organized because it did not submit a file-stamped certificate of designation from the Secretary of State. It also noted the series shared a manager and registered agent with the parent LLC. The series lost the argument that it was separate.

Lessons to take from that:

• A series is created by following the statute’s steps, including the Secretary of State filing. Writing “Series A” on a document is not enough.
• Keep each series visibly separate in practice, including its own records and how it presents itself.
• Banks, insurers, landlords and other states may be less familiar with series LLCs. Ask them before you set one up (see opening a business bank account).

The Secretary of State’s guide for organizing LLCs (printed February 2024) says a series LLC is formed with Form LLC-5.5(S) instead of the regular LLC-5.5. The filing fee is $400. After the LLC is filed, each individual series is set up by filing a Certificate of Designation (Form LLC-37.40), which costs $50. See the LLC fee table. Confirm current fees with the Secretary of State.

I did not find a source in this review that clearly says how a series is treated in every other state or for every tax, so treat those questions as open and ask a professional.

Sources: Illinois Secretary of State, Guide for Organizing Domestic Limited Liability Companies (Feb 2024); Hinshaw & Culbertson alert on the Urbana ruling (opens in a new tab) (a law firm’s summary, not the court opinion); the statute citation 805 ILCS 180/37-40.

Side by side

Questions to ask an attorney

• Would a regular LLC, an LLP or a series LLC fit what we are doing, and why?
• Is Form UPA 1001 all we need to file with the Secretary of State, and is the cost still what the Secretary of State lists?
• What would our bank, landlord and insurer need to see?
• What happens to our taxes with each structure? (A CPA question, too.)

I am not a lawyer

This page is general information, not legal or tax advice. Statutes and fees change, so confirm with the Secretary of State and an attorney. Checked Oct 30, 2026.