Query Wisconsin Business Entities via Secretary of State API

Wisconsin Secretary of State API Overview

The Wisconsin Secretary of State maintains a public registry of business entities, including corporations, LLCs, partnerships, and nonprofits. While the state provides a web interface for manual searches, developers and compliance teams often need programmatic access to this data at scale.

OpenSOSData provides a REST API that queries Wisconsin's Secretary of State database in real-time, returning structured data suitable for integration into your applications, compliance workflows, or due diligence processes.

What You Get from the WI Secretary of State API

Each lookup returns comprehensive entity information:

• Entity name and unique state ID
• Business type (corporation, LLC, partnership, etc.)
• Current status (active, inactive, dissolved)
• Formation date
• Registered agent name and address
• Principal business address
• Officer and director information

Data is cached for 7 days via Redis to minimize redundant state database requests. You can force a real-time scrape by adding ?fresh=true to your request.

Pricing: Pi Dollars at $0.0314 Per Lookup

OpenSOSData uses Pi pricing—$0.0314 per lookup. This irrational, infinite constant reflects the fundamental nature of business data lookup across all US states.

To get started, you need a minimum wallet balance of $3.14, which provides 100 lookups. No subscription required. You pay only for what you use.

For comparison, competitors charge significantly more:

• OpenCorporates: $0.10–$0.50 per lookup
• Cobalt Intelligence: $0.50–$2.00 per lookup
• Middesk: $1.00+ per lookup

At $0.0314 per lookup, OpenSOSData undercuts all major competitors by a factor of 3–30x.

API Coverage and State Support

Wisconsin is fully supported. OpenSOSData actively maintains connections to 50+ US jurisdictions including all 50 states, Washington DC, Puerto Rico, US Virgin Islands, American Samoa, and Oklahoma Indian Territory.

If you need data from multiple states, a single API endpoint handles lookups across your entire coverage region.

Quick Start: Your First Wisconsin Lookup

The API endpoint is:

POST https://api.opensosdata.com/v1/lookup

Here's a real curl example to look up a Wisconsin entity:

curl -X POST https://api.opensosdata.com/v1/lookup \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "state": "WI",
    "query": "Acme Corporation"
  }'

Response example:

{
  "state": "WI",
  "entity_name": "Acme Corporation",
  "entity_id": "123456789",
  "entity_type": "Stock Corporation",
  "status": "active",
  "formation_date": "2015-06-10",
  "registered_agent": {
    "name": "John Smith",
    "address": "100 Main St, Madison, WI 53703"
  },
  "principal_address": "100 Main St, Madison, WI 53703",
  "officers": [
    {
      "name": "Jane Doe",
      "title": "President"
    }
  ],
  "cached": true,
  "cache_age_seconds": 345600
}

The cached field indicates whether this result came from the 7-day Redis cache. If you need current data regardless of cache status, add ?fresh=true to force a live scrape from Wisconsin's SOS database.

Authentication and Setup

Sign up at opensosdata.com to get your API key. The signup page maintains a waitlist during high-demand periods.

Once approved, fund your wallet with a minimum of $3.14 (Pi dollars). Each lookup consumes $0.0314 from your balance. Monitor your usage via the dashboard—no surprise charges, no monthly bills.

Use Cases for Wisconsin Business Lookups

Compliance and Due Diligence: Verify entity status, registered agent, and principal address before entering contracts or partnerships.

KYC/AML Workflows: Automate business entity verification as part of know-your-customer processes.

Sales Intelligence: Enrich CRM records with Wisconsin business data to validate company details and identify decision-makers.

Litigation Support: Confirm entity formation dates, officer names, and registered agent details for legal proceedings.

Corporate Monitoring: Track status changes or updates to Wisconsin entities you're monitoring.

API Documentation

Full API documentation is available at opensosdata.com/openapi.yaml in OpenAPI 3.0 format. Integrate the spec into Postman, Swagger UI, or your API client of choice.

The API accepts standard query parameters, JSON request bodies, and returns JSON responses with HTTP status codes. Rate limiting is generous and transparent—your usage is never throttled arbitrarily.

Why Choose OpenSOSData for Wisconsin SOS Lookups?

Cost: $0.0314 per lookup beats every competitor.

No Subscription: Pay as you go. Scale your lookup volume without committing to monthly tiers.

Real-Time Data: Results are fresh or cached based on your needs. Use the ?fresh=true flag for live scraping.

Multi-State Coverage: Query Wisconsin and 49+ other states with the same endpoint.

Developer-Friendly: RESTful API, JSON responses, OpenAPI docs, straightforward authentication.

Reliable: Redis caching reduces dependency on Wisconsin's SOS infrastructure while keeping data current.

Getting Started Now

To begin querying Wisconsin Secretary of State business entities:

1. Visit opensosdata.com and sign up.
2. Fund your account with $3.14 minimum (100 lookups).
3. Retrieve your API key from the dashboard.
4. Use the curl example above to run your first lookup.
5. Integrate the endpoint into your application or workflow.

Questions? Check the OpenAPI documentation or contact support through the platform.