Protected and Registered Series LLC Formation Requirements in Illinois
At a glance
| Governing act and covered entity | 805 ILCS 180/37-40; ordinary Illinois LLC and designated series with limited liability. |
|---|---|
| Domestic series route | Operating agreement may establish series; limited-liability series requires filed certificate of designation for each series (§ 37-40(a)-(b), (d)). |
| Parent LLC authorization and notice | Agreement establishes series and states liability limitation; parent articles give public notice of that limitation (§ 37-40(a)-(b)). |
| Who creates a series and when | Operating agreement provides the route; series with limited liability begins on filing its certificate of designation (§ 37-40(a), (d)); no universal vote stated there. |
| Series-level public filing | Certificate states series name and, if different from parent, manager names/business addresses; executed by LLC or authorized person; $50 (§§ 37-40(d), 50-10(b)(17)). |
| Series name | Limited-liability series name begins with full parent LLC name and is distinguishable from names of other series (§ 37-40(c)). |
| Records and associated assets | Separate and distinct series records; associated assets held directly or indirectly and accounted for separately from parent and other series (§ 37-40(b)). |
| Statutory asset segregation | Separate records/assets, agreement limitation, parent-articles notice, and series certificate condition separation; reverse direction defaults unless agreement varies; express joint liability by contract remains (§ 37-40(b)). |
| Changes and termination | File designation to change series name or distinct manager list, or dissolve series; series can wind up without parent dissolution unless agreement changes rule (§ 37-40(d), (m)). |
| Outside scope and effect limits | § 37-40(b) permits express joint liability by contract and tax elections where allowed; actual creditor recovery or foreign recognition needs separate analysis. |
Requirements one by one
Agreement, notice, and designation
Under 805 ILCS 180/37-40(a), an operating agreement may establish designated series with separate rights or purposes. For limited liability under subsection (b), the agreement must provide for it, the parent articles must contain notice, each covered series must have a certificate of designation, and separate series records and asset accounting must be maintained. Subsection (d) starts a limited-liability series when its designation is filed with the Secretary of State. The certificate must identify the series and list manager or manager-authority member names and business addresses if different from the parent; the LLC or an operating-agreement designee may execute it. The current designation fee is $50 under § 50-10(b)(17).
Name and assets
Section 37-40(c) requires the limited-liability series name to begin with the parent LLC's full name and be distinguishable from other series names. Section 37-40(b) requires separate and distinct series records and associated assets held directly or indirectly, including through a nominee, and accounted for separately from the parent and every other series. The filed parent notice and designation constitute statutory notice of the limitation.
Asset limitation and ending a series
When subsection (b)'s conditions are met, a series obligation is enforceable against that series's assets and ordinarily not against parent or other-series assets; the reverse separation applies unless the operating agreement provides otherwise. The section preserves joint liability specifically accepted by contract. Under § 37-40(d), a filed designation can change the series name or distinct manager information, or identify a series being dissolved. Section 37-40(m) permits a series to wind up without dissolving the parent unless the operating agreement provides otherwise, while parent dissolution terminates its series.
What trips people up
An agreement-created series under § 37-40(a) is distinct from a series that satisfies subsection (b)'s statutory liability limitation. The designation filing alone does not replace separate asset accounting or parent-articles notice. Pending SB 3709 would change the fee if enacted; its proposed $25 designation fee is not current law.
Common questions
Does the parent need to file a certificate for each limited-liability series?
Yes. Section 37-40(b) requires a certificate of designation for each series seeking the stated limitation.
Does winding up one series dissolve the parent LLC?
Not by default. Section 37-40(m) allows a series to be wound up without dissolving the parent, subject to the operating agreement.
Statutes and sources
- 805 ILCS 180/37-40, current official series section, accessed September 27, 2026.
- 805 ILCS 180/50-10(b)(17), current official fee section, accessed September 27, 2026.
Source links
Every statute quoted above, linked, with the date we checked it.
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