> ## Documentation Index
> Fetch the complete documentation index at: https://docs.topograph.co/llms.txt
> Use this file to discover all available pages before exploring further.
# Illinois
> Country-specific identifiers, data sources, and integration details
## Start here
This guide contains public integration notes for Illinois. Use it for identifier formats, search behavior, and state-specific caveats. The live source of truth for coverage, pricing, data sources, documents, legal forms, roles, and status values is the pricing page.
Open the current catalog for supported datapoints, documents, sources, identifiers, and availability.
This jurisdiction may be in preview or limited availability. Check the live pricing page or contact support before relying on it in production.
State details below are preserved as integration notes. If a table or example conflicts with the live pricing page, use the pricing page as the source of truth and contact support.
## Table of Contents
* [Data Sources](#data-sources)
* [Company Identifiers](#company-identifiers)
* [Search Capabilities](#search-capabilities)
* [Quirks & Gotchas](#quirks--gotchas)
* [Mappings](#mappings)
* [Legal Forms](#legal-forms)
* [Entity Statuses](#entity-statuses)
* [Data Availability](#data-availability)
**API access:** `US-IL` is not yet part of the public `countryCode` enum. Contact us to enable it on your workspace. Requests sent with `countryCode: "US-IL"` will otherwise return `400` until the enum is expanded.
## Data Sources
Illinois uses a single integration against the **Illinois Secretary of State, Department of Business Services**. The register covers approximately 2.8 million entities filed under the Illinois Business Corporation Act, the General Not-for-Profit Corporation Act, the Limited Liability Company Act, and related statutes, including domestic and foreign corporations, LLCs, professional service entities, benefit corporations, agricultural cooperatives, and not-for-profit corporations.
The Illinois Business Data Transparency Act (Public Act 102-0049, effective 2022-01-01) requires the Secretary of State to publish daily bulk distributions of the business entity database. These bulk files are the sanctioned machine-readable path; Topograph uses them as the primary data source.
* **ILSOS daily bulk snapshot** (fast, onboarding). Published daily at `ilsos.gov`. Covers corporation and LLC master records, annual report data, assumed names, and manager/member rosters. The snapshot refreshes daily; individual records may lag up to 24 hours from a filing event.
* **ILSOS public inquiry portal** (authoritative, verification). The live public inquiry portal at `apps.ilsos.gov` is queried in real time for verification requests to refresh the basic profile (current legal name, entity status, registered agent, and effective date) directly from the source register. Officer rosters in verification responses continue to be served from the daily bulk snapshot.
**Mode-based routing.** Onboarding requests (`mode: "onboarding"`) are served from the daily bulk snapshot. Verification requests (`mode: "verification"`) query the live portal for the basic profile and supplement it with bulk-sourced officer data.
## Company Identifiers
### Query Identifiers
| Identifier Type | Format | Example | Notes |
| ------------------------- | ---------------------------- | ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **ILSOS File Number** | 8 digits, zero-padded | `08142220` | Assigned by the Illinois Secretary of State. **Illinois runs independent File Number sequences for corporations and LLCs.** The same 8-digit number can refer to two different entities (one corporation, one LLC). To target a specific entity, supply the Topograph compound ID. |
| **Topograph compound ID** | `C` or `L` prefix + 8 digits | `C08142220` | Prefix `C` for corporations, `L` for limited liability companies. Use this form whenever you need to target a specific entity and avoid ambiguity. |
Search by bare 8-digit File Number returns all matching entities across both the corporation and LLC sequences. Use the compound ID (`C08142220` or `L08142220`) to resolve to a single entity. The `identifiers.entityType` field in the response confirms which family was matched.
### Identifiers in API Response
| Identifier | Format | Example | Found In |
| ------------ | --------------------- | ---------- | ------------ |
| `fileNumber` | 8 digits, zero-padded | `08142220` | All entities |
## Search Capabilities
| Search Type | Pattern | Example | Match Type | Expected Results |
| --------------------- | --------------------- | ------------ | ------------------------------ | -------------------------------------------------- |
| By Name | 2-100 chars | `"Walgreen"` | Starts-with (case-insensitive) | Multiple results |
| By File Number (bare) | 8 digits | `08142220` | Exact | Up to 2 results (one corp + one LLC if both exist) |
| By Compound ID | `C` or `L` + 8 digits | `C08142220` | Exact | Single entity |
**Starts-with search.** Name search anchors on the beginning of the legal name (case-insensitive). Use fuller query strings to narrow the result set, which is capped at 100 matches.
## Quirks & Gotchas
| Quirk | Details |
| --------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **File Number sequences overlap across entity families** | Illinois maintains independent File Number sequences for corporations and LLCs. Two different entities can share the same 8-digit number. Always use the Topograph compound ID (`C` or `L` prefix) when you need to unambiguously identify a single entity. |
| **LLC status may default to active** | The bulk distribution for LLCs does not reliably expose the dissolution status field in v1. Dissolved LLCs may appear as active. The live portal provides the current status in verification mode. Use `mode: "verification"` when LLC status accuracy is required for compliance. |
| **Annual report freshness** | Corporations and LLCs file one annual report per year. Officer and address data in the snapshot may be up to 12 months old, reflecting the most recent annual filing. This is a structural property of the Illinois filing cadence, not a Topograph limitation. |
| **LLCs disclose managers and members** | Unlike many US states, Illinois LLCs disclose their managers and (where applicable) members in the public bulk distribution. `legalRepresentatives` is populated for LLCs. Do not assume an empty array for LLC entities. |
| **Limited Partnerships and LLPs are out of scope for v1** | LPs and LLPs are available through the live portal but are not included in the daily bulk distribution. They are excluded from v1 coverage. |
| **No ownership percentages** | Illinois does not collect or publish ownership percentages for any entity type. `legalRepresentatives` includes names and roles but no equity stakes. |
| **No activity codes** | The Secretary of State does not collect NAICS, NACE, or ISIC codes. A coarse 56-entry purpose code is available for corporations only and is not currently surfaced. |
| **Series LLCs** | Illinois is one of the few states that allows Series LLCs. Each individual series within a parent LLC receives its own File Number and status. Individual series are surfaced in the API as distinct entities, linked to the parent via the company record. |
| **State-level DBAs** | Assumed names (DBAs) registered at the state level are included in the bulk distribution and indexed for search. County-level DBA registrations are not included. |
| **Nonprofits are in scope** | Not-for-profit corporations filed under the Illinois General Not-for-Profit Corporation Act are included in the corporation bulk distribution and covered by this integration. Fundraising registration through the Illinois Charitable Trust Bureau is out of scope. |
## Mappings
### Legal Forms
Legal form is derived from the entity type code in the ILSOS bulk distribution, sourced from the published Corp and LLC data dictionaries. The full legal form table is available on the pricing page.
| Local Name | Standardized | Category |
| ------------------------------------------ | ----------------------- | ------------------------------ |
| Domestic Corporation | Corporation | Business Corporation Act |
| Foreign Corporation | Corporation | Business Corporation Act |
| Domestic Benefit Corporation | Corporation | Business Corporation Act |
| Foreign Benefit Corporation | Corporation | Business Corporation Act |
| Domestic Professional Service Corporation | Corporation | Business Corporation Act |
| Foreign Professional Service Corporation | Corporation | Business Corporation Act |
| Domestic Medical Corporation | Corporation | Business Corporation Act |
| Domestic Close Corporation | Corporation | Business Corporation Act |
| Domestic Not-For-Profit Corporation | NonprofitOrganization | Not-for-Profit Corporation Act |
| Foreign Not-For-Profit Corporation | NonprofitOrganization | Not-for-Profit Corporation Act |
| Religious Corporation | NonprofitOrganization | Not-for-Profit Corporation Act |
| Agricultural Cooperative | Cooperative | Ag-cooperative (unique to IL) |
| Domestic Limited Liability Company | LimitedLiabilityCompany | LLC Act |
| Foreign Limited Liability Company | LimitedLiabilityCompany | LLC Act |
| Domestic Professional Service LLC | LimitedLiabilityCompany | LLC Act |
| Foreign Professional Service LLC | LimitedLiabilityCompany | LLC Act |
| Low-Profit Limited Liability Company (L3C) | LimitedLiabilityCompany | LLC Act |
| Series Limited Liability Company | LimitedLiabilityCompany | LLC Act (unique to IL) |
| Series LLC, Individual Series | LimitedLiabilityCompany | LLC Act (unique to IL) |
The full legal form table with source codes and ISO 20275 mappings (where available) is on the [Illinois pricing page](https://topograph.co/pricing/us-il).
### Entity Statuses
Status values are sourced from the ILSOS bulk data dictionaries (Corp CORP-STATUS field and LLC LL-STATUS field) and from the live portal in verification mode. "Not Good Standing" is a derived status emitted when the current annual report has been invoiced but not yet paid.
| Status | Applies To |
| -------------------------- | ---------------- |
| Goodstanding | Corps and LLCs |
| Not Good Standing | Corps (derived) |
| Involuntary Dissolution | Corps |
| Voluntary Dissolution | Corps and LLCs |
| Withdrawn | Foreign entities |
| Merged | Corps |
| Bankruptcy Filed | Corps |
| Revoked | Corps |
| Administratively Dissolved | Corps and LLCs |
| Dissolved | Corps and LLCs |
| Converted | Corps |
| Cancelled | LLCs |
**LLC status in onboarding mode.** The bulk LLC master record does not reliably expose the dissolution status field in v1. All LLCs not explicitly marked inactive default to `Goodstanding` in onboarding mode. Use `mode: "verification"` to get a live status read from the portal when LLC status accuracy is required.
## Data Availability
| Data Point | Available | Notes |
| ----------------------------- | --------- | -------------------------------------------------------------------------------------------------------------------- |
| Company name | Yes | Current legal name |
| Company status | Partial | Reliable for corporations in both modes. LLCs: live status in verification mode; onboarding mode defaults to active. |
| Registration date | Yes | ILSOS initial filing date |
| Legal address | Yes | Street address, city, state, ZIP from the annual report |
| Legal form | Yes | Closed enum mapped to standardized categories |
| Legal representatives | Yes | Corps: president and secretary. LLCs: managers and members. LP/LLP: out of scope for v1. |
| Registered agent | Partial | Available in verification mode from the live portal. Not reliably in the bulk snapshot. |
| Assumed names (DBAs) | Yes | State-level assumed names from the bulk distribution |
| Series LLC sub-series | Yes | Each series returned as a distinct entity with its own File Number |
| Activity codes | No | Not collected by the Illinois Secretary of State |
| Shareholders | No | Not filed with the Secretary of State for any entity type |
| UBOs | No | No public beneficial ownership register at the state level |
| Trade Register Extract | Yes | Free printed PDF of the ILSOS public inquiry detail page, included at no extra charge with every data request |
| Certificates of Good Standing | Roadmap | Paid document issued by the Secretary of State. Not currently offered through Topograph. |
| Certified copies | No | Paid documents mailed by the Secretary of State; not available through the public portal |
| Financial data | No | Not collected |
| County-level DBAs | No | County-level DBA filings are not part of the Secretary of State database |
## Example API Responses
### Search by Name
```bash theme={null}
curl -X POST "https://api.topograph.co/v2/search?country=US-IL&query=Acme" \
-H "x-api-key: YOUR_API_KEY"
```
```json theme={null}
[
{
"id": "C09000001",
"legalName": "ACME MANUFACTURING, INC.",
"countryCode": "US-IL",
"matchReason": {
"matchType": "default"
},
"address": {
"region": "IL",
"countryCode": "US"
}
}
]
```
### Search by Compound ID
```bash theme={null}
curl -X POST "https://api.topograph.co/v2/search?country=US-IL&query=C09000001" \
-H "x-api-key: YOUR_API_KEY"
```
```json theme={null}
[
{
"id": "C09000001",
"legalName": "ACME MANUFACTURING, INC.",
"countryCode": "US-IL",
"matchReason": {
"matchType": "id"
}
}
]
```
### Company Profile
```bash theme={null}
curl -X POST "https://api.topograph.co/v2/company" \
-H "x-api-key: YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{"countryCode": "US-IL", "id": "C09000001", "dataPoints": ["company", "legalRepresentatives"], "mode": "onboarding"}'
```
```json theme={null}
{
"company": {
"id": "C09000001",
"countryCode": "US-IL",
"identifiers": { "fileNumber": "09000001" },
"legalName": "ACME MANUFACTURING, INC.",
"registrationDate": "2005-03-15",
"legalForm": {
"localName": "Domestic Corporation",
"standardized": "Corporation"
},
"legalAddress": {
"street": "123 Commerce Drive",
"city": "Springfield",
"region": "IL",
"postalCode": "62701",
"countryCode": "US"
},
"status": {
"active": true,
"label": "Goodstanding"
}
},
"legalRepresentatives": [
{
"role": "President",
"individual": {
"name": { "fullName": "Jane A. Smith" }
}
},
{
"role": "Secretary",
"individual": {
"name": { "fullName": "Robert B. Johnson" }
}
}
]
}
```