# OpenSOSData, free, POST /v1/bulk-lookup/upload: Business verification API

> Upload a CSV file containing entity names and states for bulk lookup.

OpenSOSData's business verification API on its Free plan. It costs $0.00 per 1,000 companies. It returns all 11 key fields we check: Registered name, Entity number, Tax ID, Entity type, Status, Good standing, Formation date, Registered agent, Principal address, Officers, Filings.
We rank 21 plans by price. [OpenSOSData's $500 monthly plan (/v1/lookup)](https://datacircle.dev/business-verification-apis/opensosdata/500-monthly-scale-cached-post-v1-lookup/llms.txt) costs the least per 1,000 companies: $5.00.

- This page: https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-bulk-lookup-upload
- Get it: https://opensosdata.com
- Request: `POST https://api.opensosdata.com/v1/bulk-lookup/upload`
- API key: with the plan, on https://opensosdata.com
- Its API docs: https://opensosdata.com/openapi.yaml
- Sold by: OpenSOSData (https://opensosdata.com)
- Checked: 2026-10-27

## In the answer

- Completeness: 100%
- Registered name: ✓
- Entity number: ✓
- Tax ID: ✓
- Entity type: ✓
- Status: ✓
- Good standing: ✓
- Formation date: ✓
- Registered agent: ✓
- Principal address: ✓
- Officers: ✓
- Filings: ✓

## Price

- $ per 1,000 companies: $0.00
- Per: result
- Billing: free

## Charges

- Also pays for: from the same budget: Look up a business entity or UCC filing by name and state · Submit a bulk entity lookup job · Check business name availability

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Upload a CSV file containing entity names and states for bulk lookup.

## Data

- Freshness: live
- Keep data: no limit
- Use data: "You agree NOT to use OpenSOSData to: Harass, stalk, dox, or target individuals. Build consumer credit reports or take consumer-impacting decisions. We are not a consumer reporting agency under the Fair Credit Reporting Act and our data may not be used for any FCRA-covered purpose. Violate any applicable law or regulation, including data protection and anti-spam laws. Resell or republish raw API responses without significant transformation, enrichment, or aggregation. Attempt to reverse-engineer, decompile, or scrape our infrastructure. Exceed published rate limits or attempt to circumvent billing controls. Use the service to compete directly with OpenSOSData by reselling identical lookups."

## Plan

- Pay: $0
- You get: 10 credits
- Enough for: 10 results, once

## Rate limit

- Per second: 0.17
- Batch: 1,000

## Speed

- Answer: by polling

## The call

- You send: Content-Type header "text/csv", CSV file body with columns entity_name and state. Optional: search_by, max_results, type, cache_preference
- Path: /v1/bulk-lookup/upload

## About the plan

- Plan: Free
- Who can get it: new accounts, once on signup, no credit card required

## The 74 fields the plan's answer can hold

searched name, entity name, entity type, entity type description, entity ID, state entity ID, old entity ID, EIN, status, status reason, sub-status, standing, annual report standing, registered agent standing, other standing, revenue standing, statement status, next statement due date, formation date, effective date, dissolution date, inactive date, revival date, duration date, registered agent name, registered agent address, registered agent city, registered agent state, registered agent ZIP code, registered agent mailing address, principal address, principal city, principal state, principal ZIP code, mailing address, mailing city, mailing state, mailing ZIP code, officers, filing history, annual reports, annual report due date, last annual report, last event, event date filed, event effective date, profit or nonprofit, industry, NAICS code, NAICS description, jurisdiction, authorized shares, foreign legal name, fictitious name, number of employees, primary county, county, section of law, service of process name, service of process address, fiscal month and day, periodic report month, detail screenshot URL, search results screenshot URL, filing history screenshot URL, filing history second screenshot URL, scraped at, data as of, cached, stale, result source, scraper version, scraper built at, data completeness

## OpenSOSData's plans (10)

- [OpenSOSData, free, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-bulk-lookup-upload/llms.txt): $0.00 per 1,000, 100% complete, live
- [OpenSOSData, free cached, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/free-cached-post-v1-bulk-lookup-upload/llms.txt): $0.00 per 1,000, 100% complete, stored
- [OpenSOSData, $50 pack, Starter, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/50-pack-starter-post-v1-bulk-lookup-upload/llms.txt): $100.00 per 1,000, 100% complete, live
- [OpenSOSData, $100 pack, Growth, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/100-pack-growth-post-v1-bulk-lookup-upload/llms.txt): $75.00 per 1,000, 100% complete, live
- [OpenSOSData, $250 pack, Scale, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/250-pack-scale-post-v1-bulk-lookup-upload/llms.txt): $50.00 per 1,000, 100% complete, live
- [OpenSOSData, $500 pack, Enterprise, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/500-pack-enterprise-post-v1-bulk-lookup-upload/llms.txt): $31.40 per 1,000, 100% complete, live
- [OpenSOSData, $100 monthly, Starter Cached, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/100-monthly-starter-cached-post-v1-bulk-lookup-upload/llms.txt): $10.00 per 1,000, 100% complete, stored
- [OpenSOSData, $250 monthly, Growth Cached, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/250-monthly-growth-cached-post-v1-bulk-lookup-upload/llms.txt): $7.50 per 1,000, 100% complete, stored
- [OpenSOSData, $500 monthly, Scale Cached, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/500-monthly-scale-cached-post-v1-bulk-lookup-upload/llms.txt): $5.00 per 1,000, 100% complete, stored
- [OpenSOSData, $1,000 monthly, Enterprise Cached, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/1000-monthly-enterprise-cached-post-v1-bulk-lookup-upload/llms.txt): $3.14 per 1,000, 100% complete, stored

## OpenSOSData's calls (3)

- `POST /v1/lookup`: [OpenSOSData, free, POST /v1/lookup](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-lookup/llms.txt)
- `POST /v1/bulk-lookup`: [OpenSOSData, free, POST /v1/bulk-lookup](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-bulk-lookup/llms.txt)
- `POST /v1/bulk-lookup/upload`: [OpenSOSData, free, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-bulk-lookup-upload/llms.txt)

## OpenSOSData's APIs (1)

- [OpenSOSData: business verification API pricing, 10 plans, POST /v1/bulk-lookup/upload](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-bulk-lookup-upload/llms.txt)

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-10-27.

- https://opensosdata.com
- https://opensosdata.com/docs/
- https://opensosdata.com/docs/changelog.html
- https://opensosdata.com/llms.txt
- https://opensosdata.com/openapi.yaml
- https://opensosdata.com/terms