Companies House API: rate limits, cost and access (2026)

An honest comparison between Prometiam and the UK Companies House public API. The CH API is the canonical, free, government-maintained source of truth for UK company data, and for UK-only use cases that fit inside its 600 requests / 5-minute rate limit, you should keep using it. Prometiam is the right alternative when you also need EU coverage, need sanctions screening in the same API, want normalized corporate events instead of raw filings, or exceed the CH rate limit.

Why teams look for an alternative

Where Prometiam adds value

Prometiam is a layer on top, not a re-hosted copy. Its UK data comes from the same official Companies House bulk product files plus the daily delta feed and The Gazette for insolvency notices. It adds further coverage on the same endpoints (Spain via BORME, France via BODACC, Norway via Brønnøysundregistrene with companies and directors, plus Ireland and Poland at company level only — no directors or UBO there), sanctions and US export-control screening across 6 sources (EU, UN, OFAC, UK OFSI, French gels, and the US Consolidated Screening List / BIS Entity List, Denied Persons, ITAR) covering 44,000+ active entities, and normalized typed corporate events. UK beneficial ownership is covered via PSC data. PEP screening is beta and Spain-only (no relatives or close associates); no adverse-media, and no natural-person identity verification.

Pricing and rate limits

CH is free with a hard ceiling. Prometiam has a free tier (1,000 calls/month); paid starts at EUR 9.99/mo (Starter), with sanctions screening on the EUR 29.99/mo Professional tier (100,000 calls/month, 300 rpm), and higher Scale and Enterprise tiers above.

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At a glance

PrometiamCompanies House API
CoverageUK + Spain + France + Ireland + Poland + NorwayUK only
PricingPublic — €0 / €9.99 / €29.99 / CustomFree
Rate limitPer-tier; 300 rpm and 100,000 calls/month on Professional600 / 5min hard ceiling
AuthBearer rk_live_*API key (HTTP Basic)
Sanctions screeningIncluded on ProfessionalNot provided
Corporate eventsNormalized into typed eventsRaw filings — you classify them
PSC dataIncluded in person/company endpointsAvailable via separate endpoints
Insolvency noticesIncluded in /search and /records/{id}Available via separate Gazette feed
SLA / supportYes on paid tiersNone — public service

Frequently asked questions

Is the Companies House API really free?
Yes. The UK government provides it free as a public service. There is no paid tier — meaning the 600 requests / 5-minute rate limit is the hard ceiling.
Does Prometiam replace the Companies House API?
For UK-only low-volume use cases, no — and we would not recommend it. For multi-country (UK + EU) use cases, batch enrichment that exceeds the CH rate limit, or any workflow that needs sanctions screening in the same call, yes.
Where does Prometiam UK data come from?
From the official Companies House sources — bulk product files plus the daily delta feed, plus The Gazette for insolvency notices. Same data lineage as the CH API; Prometiam normalizes it into a multi-country schema and adds sanctions screening.
Can I use both the CH API and Prometiam together?
Yes. Common pattern: use CH for real-time filing-event consumption and Prometiam for batch enrichment, multi-country queries, and sanctions screening.
Does Prometiam cover Persons with Significant Control (PSC)?
Yes. PSC data for UK companies is embedded in /companies/{id} and /people/{id} responses, and the director-network graph at /directors/network exposes cross-company linkages.
How does pricing compare?
CH is free with a hard rate limit. Prometiam has a free tier (1,000 calls/month); paid starts at €9.99/mo for 10,000 calls/month (Starter), or €29.99/mo for 100,000 calls/month with full sanctions screening (Professional). The right comparison is "free CH + paid sanctions vendor + paid EU vendor" vs "Prometiam Professional at €29.99/mo".