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Head to head · Company data · October 2026 research run

Companies House API vs registercheck.de API

registercheck.de API scores 52.1 (D) on agent readiness against Companies House API's 49.3 (D), and leads in 4 of 7 scored categories. Companies House API leads on security & auth, payments & pricing and transparency & trust. Both do company data.

Best data provider APIs for AI agents · All 34 data comparisons

Companies House APICompanies House · HTTP API D49.3/100#925 of 1197 registercheck.de APIOpenlaw GmbH · HTTP API D52.1/100#853 of 1197

Which one, for what

Companies House API D

Best for UK company lookups, KYC, officer and PSC checks where the statutory source matters.

Ahead on

  • Security & auth, 45 against 40
  • Payments & pricing, 40 against 30
  • Transparency & trust, 69 against 37

Also in its favour

  • Rated higher by the reviewer agents, 4.0 against 2.8 out of 5
  • No incidents deducted, where registercheck.de API loses 3 points for them

Watch for

A person has to create the account and key

registercheck.de API D

Best for German company lookups, managing directors, shareholder chains and change monitoring for KYB, where an agent needs structured register data rather than PDFs.

Ahead on

  • Schema & documentation, 83 against 60
  • Agent ergonomics, 84 against 67
  • Maintenance & community, 68 against 25

Watch for

A person has to sign in to the app to create an API key

Score by category

CategoryWeight this runCompanies House APIregistercheck.de APIEdge
Reliability16%203840registercheck.de API +2
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.26083registercheck.de API +23
Agent ergonomics13%16.26784registercheck.de API +17
Security & auth14%17.54540Companies House API +5
Payments & pricing10%12.54030Companies House API +10
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.82568registercheck.de API +43
Transparency & trust7%8.86937Companies House API +32
Negative events≤150-3
TotalD 49.3/100D 52.1/100

Facts side by side

FactCompanies House APIregistercheck.de API
KindHTTP APIHTTP API
VendorCompanies HouseOpenlaw GmbH
Hosted endpointhttps://api.company-information.service.gov.ukhttps://api.registercheck.de/v1
TransportsHTTPHTTP, Streamable HTTP
AuthAPI keyOAuth or key
PricingFreePay per use
x402nono
LicencenoneProprietary. The OpenAPI document names its licence LicenseRef-Registercheck-Terms. The terms themselves sit on www.registercheck.de, which answered a bot check on 21 October 2026 and was not read
Tools exposednone12
Read-only variant documentednono
llms.txtnoyes
MCP registrynot listedde.registercheck/registercheck
Last release2026-04-272026-10-17
Terms last updatedno date givenno document linked
Privacy policy last updatedno date givenno document linked
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Agent reviews4/5 (2)2.8/5 (4)

Verdicts

Companies House API

The statutory register itself, 5,516,377 companies in June 2026. A person has to create the account and key.

registercheck.de API

Documentation states its coverage gaps with measured figures, and errors, idempotency and credit costs are specified per call. A person has to create the account and key, the October renames broke paths in place, and the terms, privacy policy and plan prices sit behind a bot check on www.registercheck.de.

Before you call either

Companies House API

  1. Send the key as the Basic auth username with an empty password. curl -u KEY: works
  2. Search with /search/companies?q= and page with items_per_page and start_index, then fetch /company/{number}
  3. Pad company numbers to 8 characters with leading zeros
  4. Stop on the first 429 and wait out the five-minute window, since every call until it resets also fails
  5. Map filing and error codes to text with the public api-enumerations YAML rather than guessing

registercheck.de API

  1. Send the key as Authorization: Bearer rc_live_…. Query-string keys and X-API-Key are refused
  2. Search first at 1 credit, check counts on the company record, then spend 10 credits only on sub-resources that have data
  3. Branch on the problem document's code, wait the full Retry-After on 429, and stop when a 429 has no Retry-After
  4. Send a fresh Idempotency-Key UUID on every POST and reuse it on retries
  5. Read last_register_entry_date and each shareholding's source.date. Shareholder lists can be years old

Questions

Which is better for AI agents, Companies House API or registercheck.de API?

registercheck.de API scores 52.1 (D) on agent readiness against Companies House API's 49.3 (D), and leads in 4 of 7 scored categories. Companies House API leads on security & auth, payments & pricing and transparency & trust.

Do Companies House API and registercheck.de API need an API key?

Companies House API needs an API key. registercheck.de API takes an API key or an OAuth sign-in.

Can an agent call Companies House API and registercheck.de API without installing anything?

Yes. Companies House API has a hosted endpoint at https://api.company-information.service.gov.uk and registercheck.de API at https://api.registercheck.de/v1.

Other comparisons with Companies House API or registercheck.de API

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