# Companies House, free, GET /advanced-search/companies: Business verification API

> Advanced search for a company

Companies House's business verification API on its Free plan. It costs $0.00 per 1,000 companies. It returns 1 of the 11 key fields we check: Entity number.
You get up to 5,184,000 calls a month.
Half of the 31 plans we rank by price cost $19.90 per 1,000 companies or less. This plan and 1 other tie for the lowest price per 1,000 companies of the 31 plans.

- This page: https://datacircle.dev/business-verification-apis/companies-house/free-get-advanced-search-companies
- Get it: https://www.api.gov.uk/ch/companies-house/
- Request: `GET https://api.company-information.service.gov.uk/advanced-search/companies`
- API key: with the plan, on https://www.api.gov.uk/ch/companies-house/
- Its API docs: https://developer-specs.company-information.service.gov.uk/companies-house-public-data-api/reference/search/advanced-company-search
- Sold by: Companies House (https://www.gov.uk/government/organisations/companies-house)
- Checked: 2026-10-30

## In the answer

- Completeness: 9%
- Entity number: ✓

## Price

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

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Advanced search for a company

## Data

- Keep data: no limit
- Use data: "Companies House imposes no rules or requirements on how the information on the public register is used." "We place no restriction on how the information is used after purchase, other than the following:" "all customers, including bulk customers, must take their own legal advice regarding possible breach of third party copyright" "customers cannot reproduce the Crown insignia" "if information is used from guidance notes, the website, publications or statistical tables the customer must credit Companies House as the source of the information". Developer guidelines: "We reserve the right to ban without notice applications that regularly exceed or attempt to bypass the rate limits."

## Plan

- Pay: $0
- Enough for: 5,184,000 calls a month

## Rate limit

- Per second: 2
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: nothing required. Optional: company_name_includes, company_name_excludes, company_status, company_subtype, company_type, dissolved_from, dissolved_to, incorporated_from, incorporated_to, location, sic_codes, size, start_index
- Method: GET
- Path: /advanced-search/companies

## About the plan

- Plan: Free
- Who can get it: anyone with a Companies House user account

## The 19 fields the plan's answer can hold

ETag, kind, total results, top hit, company name, company number, company status, company type, company subtype, date of creation, date of cessation, address line 1, address line 2, locality, region, postal code, country, SIC codes, link to company

## Companies House's plans (1)

- [Companies House, free, GET /advanced-search/companies](https://datacircle.dev/business-verification-apis/companies-house/free-get-advanced-search-companies/llms.txt): $0.00 per 1,000, 9% complete

## Companies House's calls for this API (2)

- `GET /advanced-search/companies`: [Companies House, free, GET /advanced-search/companies](https://datacircle.dev/business-verification-apis/companies-house/free-get-advanced-search-companies/llms.txt)
- `GET /search/companies`: [Companies House, free, GET /search/companies](https://datacircle.dev/business-verification-apis/companies-house/free-get-search-companies/llms.txt)

## Companies House's APIs (4)

- [Companies House: company enrichment API pricing, 1 plan](https://datacircle.dev/company-enrichment-apis/companies-house/free/llms.txt)
- [Companies House: people enrichment API pricing, 1 plan](https://datacircle.dev/person-enrichment-apis/companies-house/free/llms.txt)
- [Companies House: business verification API pricing, 1 plan, GET /advanced-search/companies](https://datacircle.dev/business-verification-apis/companies-house/free-get-advanced-search-companies/llms.txt)
- [Companies House: people search API pricing, 1 plan, GET /company/{company_number}/officers](https://datacircle.dev/people-search-apis/companies-house/free-get-company-company-number-officers/llms.txt)
- [Companies House: people search API pricing, 1 plan, GET /company/{company_number}/persons-with-significant-control](https://datacircle.dev/people-search-apis/companies-house/free-get-company-company-number-persons-with-significant-control/llms.txt)
- [Companies House: people search API pricing, 1 plan, GET /search/officers](https://datacircle.dev/people-search-apis/companies-house/free-get-search-officers/llms.txt)

## Companies House: business verification API alternatives

- [OpenSOSData, free, POST /v1/lookup](https://datacircle.dev/business-verification-apis/opensosdata/free-post-v1-lookup/llms.txt): $0.00 per 1,000, 100% complete, live
- [OpenCorporates, free](https://datacircle.dev/business-verification-apis/opencorporates/free/llms.txt): $0.00 per 1,000, 27% complete, stored
- [Registry Lookup, free](https://datacircle.dev/business-verification-apis/registry-lookup/free/llms.txt): $0.00 per 1,000, 27% complete, 7 days
- [Zephira, free](https://datacircle.dev/business-verification-apis/zephira/free/llms.txt): $0.00 per 1,000, 9% complete

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-10-30.

- https://developer-specs.company-information.service.gov.uk/api.ch.gov.uk-specifications/swagger-2.0/spec/search-companies.json
- https://developer-specs.company-information.service.gov.uk/companies-house-public-data-api/reference/search/advanced-company-search
- https://developer-specs.company-information.service.gov.uk/guides/rateLimiting
- https://developer.company-information.service.gov.uk/developer-guidelines
- https://developer.company-information.service.gov.uk/get-started
- https://www.api.gov.uk/ch/companies-house/
- https://www.gov.uk/government/publications/companies-house-accreditation-to-information-fair-traders-scheme/public-task-copyright-and-crown-copyright