# CompanyStack, free: Company discovery API

> Full-text search across about 6 million UK companies.

CompanyStack's Free plan for the company discovery API costs $0.00 per 1,000 companies. We check each provider's docs for 13 fields. CompanyStack's docs list 4: Industry, Type and status, Headquarters, Parents.
We haven't run CompanyStack through [our company discovery API benchmark](https://datacircle.dev/best-company-discovery-api.txt) yet.
This plan is free. We rank 1,326 plans for company discovery APIs by price. Half the plans cost $0.498 or less per 1,000 companies. [See the best free company discovery API plan.](https://datacircle.dev/best-company-discovery-api.txt)
[StackScan's $189 monthly plan](https://datacircle.dev/company-discovery-apis/stackscan/189-monthly-enterprise-post-v1-tech-lookup-lists/llms.txt) is the cheapest paid plan per 1,000 companies. StackScan's $189 monthly plan charges nothing per call. You get as many companies as StackScan's rate limit allows. [Seltz's pay-as-you-go plan](https://datacircle.dev/company-discovery-apis/seltz/pay-as-you-go-pay-as-you-go-post-v1-search-search-base/llms.txt) costs the least for 10,000 companies a month: $0.03.
[PeopleSearch.im's $5 pack](https://datacircle.dev/company-discovery-apis/peoplesearch-im/5-pack/llms.txt) covers any number of companies. PeopleSearch.im's $5 pack costs less up front than StackScan's $189 monthly plan.
[GetProspect](https://datacircle.dev/company-discovery-apis/getprospect/49-monthly/llms.txt), [Hunter](https://datacircle.dev/company-discovery-apis/hunter/49-monthly-starter-post-discover/llms.txt) and [PeopleSearch.im](https://datacircle.dev/company-discovery-apis/peoplesearch-im/5-pack/llms.txt) are the best company discovery API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/company-discovery-apis/companystack/free
- [Company discovery API in 2026: the best of 100+ compared](https://datacircle.dev/best-company-discovery-api.txt)
- Get it: https://companystack.co.uk/pricing?product=api&utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- Request: `GET https://api.companystack.co.uk/company/search`
- API key: with the plan, on https://companystack.co.uk/pricing?product=api&utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- Its API docs: https://companystack.co.uk/docs/reference?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing#op/GET/company/search
- Sold by: CompanyStack (https://companystack.co.uk?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing)
- Checked: 2026-11-10

## In the answer

- Completeness: 31%
- Industry: ✓
- Type and status: ✓
- Headquarters: ✓
- Parents: ✓

## Price

- $ per 1,000 companies: $0.00
- Per: page of 10
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Most per search: 10
- Also pays for: Filed accounts, year by year · Company health score · from the same budget: Autocomplete company names · Get company by number · Newly incorporated companies · Search industries by keyword · Get all SIC codes with company counts · One area's business figures · Group structure: who controls whom

## Overage

- Units cap: hard

## Not found

- $ per 1,000 calls that find nothing: $0.00

## In their words

- Their pitch: Full-text search across about 6 million UK companies.

## Data

- Freshness: stored
- Countries: United Kingdom
- Keep data: no limit
- Use data: "17.2 While you have an account, we give you a non-exclusive, non-transferable licence to use the Service and its outputs (including API responses, exports and PDF reports) for your internal business purposes. You may keep outputs in your own business records, including after your account ends, and share them with your professional advisers, auditors and regulators." "17.3 You may include limited extracts of our outputs in your own products or publications, provided you credit "CompanyStack" and the original source (for example "Source: Companies House via CompanyStack"). You must not redistribute, resell or publish our data in bulk, or build a competing database from it, without our written agreement." "17.5 You must not present our outputs as a credit rating, as a credit reference about an individual, or as checked, verified, certified or endorsed by us or by Companies House beyond what their labels say." "14.4 If you share or publish our data as clauses 15B and 17 allow, you must keep the attribution statement each source's licence requires (for Companies House data: "Contains public sector information licensed under the Open Government Licence v3.0.") and must not suggest that Companies House or any other source endorses you, us or your use of the data."

## Plan

- Pay: £0
- You get: 1,000 requests a day
- Enough for: 1,000 pages a day

## Rate limit

- Per day: 1,000
- Per second: 0.5 (30 a minute)
- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: at least one of q, status, sic, postcode or town. Optional: limit, offset, incorporated_from, incorporated_to
- Method: GET
- Path: /company/search

## About the plan

- Plan: Free
- Who can get it: businesses, sole traders, charities, public bodies and other organisations, for use in their trade, business or profession (no consumers), aged 18 or over

## The 62 fields the plan's answer can hold

company number, company name, company status, company type, date of creation, dissolution date, registered office address, at default address, default address statement, default address changed on, country of origin, SIC code, accounts next due date, accounts last made up to, accounts category, accounts reference day, accounts reference month, accounts overdue, confirmation statement next due date, confirmation statement last made up to, confirmation statement overdue, total charges, outstanding charges, part-satisfied charges, satisfied charges, previous names, matched former name, matched former name changed on, matched former name label, data as at, data last updated, data freshness source, data etag, record source, entity kind, company kind, UK deadlines apply, public register name, public register URL, public register entry, parent company number, parent company name, parent company country, parent company status, UK establishments, update statement next due date, update statement last made up to, update statement overdue, people term singular, people term plural, general partners, limited partners, total results, total capped, limit, offset, paging limited, requested offset, notice, upgrade URL, former name matches, query

## CompanyStack's plans (6)

- [CompanyStack, free](https://datacircle.dev/company-discovery-apis/companystack/free/llms.txt): $0.00 per 1,000, 31% complete, stored
- [CompanyStack, £29 monthly, Starter, GET /company/search](https://datacircle.dev/company-discovery-apis/companystack/29-monthly-starter-get-company-search/llms.txt): $0.0013 per 1,000, 31% complete, stored
- [CompanyStack, £99 monthly, Business, GET /company/search](https://datacircle.dev/company-discovery-apis/companystack/99-monthly-business-get-company-search/llms.txt): $0.00044 per 1,000, 31% complete, stored
- [CompanyStack, £288 yearly, Starter (yearly), GET /company/search](https://datacircle.dev/company-discovery-apis/companystack/288-yearly-starter-yearly-get-company-search/llms.txt): $0.0011 per 1,000, 31% complete, stored
- [CompanyStack, £984 yearly, Business (yearly), GET /company/search](https://datacircle.dev/company-discovery-apis/companystack/984-yearly-business-yearly-get-company-search/llms.txt): $0.00036 per 1,000, 31% complete, stored
- [CompanyStack, contact us, Enterprise, GET /company/search](https://datacircle.dev/company-discovery-apis/companystack/contact-us-enterprise-get-company-search/llms.txt): 31% complete, stored

## CompanyStack's calls for this API (2)

- `GET /company/search`: [CompanyStack, free](https://datacircle.dev/company-discovery-apis/companystack/free/llms.txt)
- `GET /prospects`: [CompanyStack, £29 monthly, Starter, GET /prospects](https://datacircle.dev/company-discovery-apis/companystack/29-monthly-starter-get-prospects/llms.txt)

## CompanyStack's APIs (4)

- [CompanyStack: company discovery API pricing, 6 plans](https://datacircle.dev/company-discovery-apis/companystack/free/llms.txt)
- [CompanyStack: company enrichment API pricing, 6 plans](https://datacircle.dev/company-enrichment-apis/companystack/free/llms.txt)
- [CompanyStack: company hierarchy API pricing, 6 plans](https://datacircle.dev/company-hierarchy-apis/companystack/free/llms.txt)
- [CompanyStack: business verification API pricing, 5 plans](https://datacircle.dev/business-verification-apis/companystack/29-monthly/llms.txt)

## CompanyStack: company discovery API alternatives

- [graph8, $499 monthly](https://datacircle.dev/company-discovery-apis/graph8/499-monthly/llms.txt): $0.00012 per 1,000, 69% complete, stored
- [Hunter, $921.50 yearly, Data Platform, 97,000 Search credits, POST /discover](https://datacircle.dev/company-discovery-apis/hunter/921-50-yearly-data-platform-97000-search-credits-post-discover/llms.txt): $0.00036 per 1,000, 54% complete, stored
- [Argorant, $49 monthly](https://datacircle.dev/company-discovery-apis/argorant/49-monthly/llms.txt): $0.00038 per 1,000, 62% complete, stored
- [The Swarm, $12,000 yearly, Enterprise 2500, POST /v3/companies/search](https://datacircle.dev/company-discovery-apis/the-swarm/12000-yearly-enterprise-2500-post-v3-companies-search/llms.txt): $0.00039 per 1,000, 0% complete, stored

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-10.

- https://companystack.co.uk/developers?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- https://companystack.co.uk/docs?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- https://companystack.co.uk/docs/reference?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- https://companystack.co.uk/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- https://companystack.co.uk/pricing?product=api&utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing
- https://companystack.co.uk/terms?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=company-discovery-api-pricing