Secretary of State API: How to Search Business Records Across All U.S. States

Published 2026-04-11 by OpenSOSData

Every U.S. state maintains its own Secretary of State database for business entity registrations. There is no federal registry. If you need to verify a business entity and do not know which state it is registered in, you need to search up to 50 different state systems.

The Multi-State Challenge

Each state SOS website has its own search interface, CAPTCHA protections, and response format. Building and maintaining scrapers for all 50 states is a significant engineering effort that breaks every time a state updates its website.

How an API Layer Solves This

A Secretary of State API abstracts away individual state systems. Your application makes one POST request and receives standardized JSON regardless of the state.

curl -X POST https://api.opensosdata.com/v1/lookup \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"entity_name": "Example Corp", "state": "DE"}'

OpenSOSData Coverage

OpenSOSData supports 30 U.S. states with real-time lookups, expanding to 48+ by April 15, 2026. Each lookup costs $0.0314 with no subscription.

Nationwide Search

The OpenSOSData portal offers a Smart Nationwide Search that queries states in priority order (starting with Delaware) and stops on first match. You only pay for states actually searched.

For a Python example, see our Python guide. For per-state docs, visit the state coverage page.