OpenSOSData vs Middesk
Comparing OpenSOSData and Middesk for U.S. business entity search API.
| Feature | OpenSOSData | Middesk |
|---|---|---|
| Price per lookup | $0.0314 | Custom enterprise |
| Subscription required | No | Enterprise contract |
| States covered | 30 (48+ by Apr 15) | US |
| API access | REST JSON API | REST API |
| Pay as you go | Yes (free tier available) | Varies |
| Data source | Real-time state SOS databases | Varies |
Key Differences
Middesk offers business identity verification with KYB features beyond basic SOS lookups. Their pricing starts at $1.00+ per lookup and typically requires an enterprise sales conversation. OpenSOSData is self-serve at $0.0314 per lookup.
Middesk bundles SOS data with additional verification features. If you only need SOS entity lookups, OpenSOSData is 32x cheaper and requires no sales process.
Why Teams Choose OpenSOSData
- $0.0314 per lookup with no subscription or contract
- Real-time data queried directly from state Secretary of State databases
- Self-serve signup with instant API access
- 30 states live now, expanding to 48+ by April 15, 2026