Companies House
Companies House is the UK government executive agency and trading fund responsible for incorporating and dissolving limited companies and registering company information in Great Britain. The Companies House REST API provides a free, open, and standardised way to search and retrieve company registration data, including company profiles, officer appointments, persons of significant control, filing history, charges, and insolvency records. Developers can also access a real-time Streaming API that delivers changes to Companies House data as they happen, enabling applications to stay up-to-date without polling. Authentication is handled via API key using HTTP Basic Auth, and all access is provided free of charge with a generous rate limit.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Companies House the way a machine reads it — 146 machine-readable artifacts across 9 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Companies House scores 50.8/100 (developing), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Companies House
Each block below is one kind of artifact we hold for Companies House. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 9
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
Companies House Streaming API
The Companies House Streaming API delivers real-time changes to Companies House data via long-running HTTP connections. It streams updates across nine data categories including ...
Companies House charges API
Charges
Companies House filingHistory API
Filing history
Companies House insolvency API
Insolvency
Companies House officerDisqualifications API
Officer disqualifications
Companies House officers API
Officers
Companies House personsWithSignificantControl API
Persons with significant control
Companies House registeredOfficeAddress API
Registered office address
Scroll within the panel for all 9 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Companies House Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Companies House Finops
FINOPSSemantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Companies House Context
JSON-LDSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
Companies House API Rules
SPECTRALJSON Schema 127
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
accountInformation
JSON SCHEMAaccountingReferenceDate
JSON SCHEMAaccountPeriodFrom
JSON SCHEMAaccountPeriodTo
JSON SCHEMAaccountsInformation
JSON SCHEMAaccountsRequired
JSON SCHEMAaddress
JSON SCHEMARegistered Office Address
JSON SCHEMAadvanced_top_hit
JSON SCHEMAadvancedCompany
JSON SCHEMAA list of companies
JSON SCHEMAalphabetical_top_hit
JSON SCHEMAAlphabetical company
JSON SCHEMAList of companies
JSON SCHEMAalterationsDesc
JSON SCHEMAannotation
JSON SCHEMAannualReturnInformation
JSON SCHEMAappointedTo
JSON SCHEMAappointmentLinkTypes
JSON SCHEMAappointmentList
JSON SCHEMAassociatedFiling
JSON SCHEMAbranchCompanyDetails
JSON SCHEMAcase
JSON SCHEMAcaseDates
JSON SCHEMAcharge_links
JSON SCHEMAchargeDetails
JSON SCHEMAchargeList
JSON SCHEMAclassificationDesc
JSON SCHEMACommonSearch
JSON SCHEMACommonSearchItems
JSON SCHEMAcompanyDetails
JSON SCHEMAcompanyExemptions
JSON SCHEMAcompanyInsolvency
JSON SCHEMAcompanyProfile
JSON SCHEMAcompanyRegister
JSON SCHEMACompanySearch
JSON SCHEMACompanySearchItems
JSON SCHEMAcompanyUKEstablishments
JSON SCHEMAconfirmationOfStatementInformation
JSON SCHEMAcontactDetails
JSON SCHEMAcorporateAnnotation
JSON SCHEMAcorporateDisqualification
JSON SCHEMAcorporateIdent
JSON SCHEMAdateOfBirth
JSON SCHEMAdisqualification
JSON SCHEMADisqualifiedOfficerAddress
JSON SCHEMADisqualifiedOfficerSearch
JSON SCHEMADisqualifiedOfficerSearchItems
JSON SCHEMARegistered Office Address
JSON SCHEMAdissolved_top_hit
JSON SCHEMADissolved company
JSON SCHEMAList of dissolved companies
JSON SCHEMAexemptionItem
JSON SCHEMAexemptions
JSON SCHEMAfileWithin
JSON SCHEMAfilingHistoryItem
JSON SCHEMAfilingHistoryItemLinks
JSON SCHEMAfilingHistoryList
JSON SCHEMAforeignCompanyDetails
JSON SCHEMAformerNames
JSON SCHEMAinsolvency_case_links
JSON SCHEMAinsolvency_cases
JSON SCHEMAitemLinkTypes
JSON SCHEMAlast_variation
JSON SCHEMAlastAccounts
JSON SCHEMAlinks
JSON SCHEMAlinksDirectorsRegister
JSON SCHEMAlinksItems
JSON SCHEMAlinksListLLPMembers
JSON SCHEMAlinksListLLPUsualResidentialAddress
JSON SCHEMAlinksListMembers
JSON SCHEMAlinksListUsualResidentialAddress
JSON SCHEMALinksModel
JSON SCHEMAlinksPersonsWithSignificantControlRegister
JSON SCHEMAlinksSecretaryRegister
JSON SCHEMAlinksType
JSON SCHEMAlinkTypes
JSON SCHEMAMatchesModel
JSON SCHEMAnameElements
JSON SCHEMAnaturalDisqualification
JSON SCHEMAnextAccounts
JSON SCHEMAnotificationList
JSON SCHEMAOfficerAddress
JSON SCHEMAofficerAppointmentSummary
JSON SCHEMAOfficerDateOfBirth
JSON SCHEMAofficerLinkTypes
JSON SCHEMAofficerList
JSON SCHEMAOfficerSearch
JSON SCHEMAOfficerSearchItems
JSON SCHEMAofficerSummary
JSON SCHEMAoriginatingRegistry
JSON SCHEMAparticularDesc
JSON SCHEMApermission_to_act
JSON SCHEMApersons_entitled
JSON SCHEMAPersonswithsignificantcontrolAddress
JSON SCHEMAPersonswithsignificantcontrolDateOfBirth
JSON SCHEMAPersonswithsignificantcontrolSearch
JSON SCHEMAPersonswithsignificantcontrolSearchItems
JSON SCHEMApractitionerAddress
JSON SCHEMApractitioners
JSON SCHEMAPrevious company name
JSON SCHEMApreviousCompanyNames
JSON SCHEMAprincipalOfficeAddress
JSON SCHEMApscExemptAsSharesAdmittedOnMarketItem
JSON SCHEMApscExemptAsTradingOnEuRegualatedMarketItem
JSON SCHEMApscExemptAsTradingOnRegulatedMarketItem
JSON SCHEMApscExemptAsTradingOnUkRegualatedMarketItem
JSON SCHEMAreason
JSON SCHEMAregisteredItems
JSON SCHEMAregisteredOfficeAddress
JSON SCHEMAregisterListDirectors
JSON SCHEMAregisterListLLPMembers
JSON SCHEMAregisterListLLPUsualResidentialAddress
JSON SCHEMAregisterListMembers
JSON SCHEMAregisterListPersonsWithSignificantControl
JSON SCHEMAregisterListSecretaries
JSON SCHEMAregisterListUsualResidentialAddress
JSON SCHEMAregisters
JSON SCHEMAresolution
JSON SCHEMASearch
JSON SCHEMASearchItems
JSON SCHEMAsecuredDetailsDesc
JSON SCHEMAself_links
JSON SCHEMAserviceAddress
JSON SCHEMAtransaction_links
JSON SCHEMAtransactions
JSON SCHEMAScroll within the panel for all 127 ·
Examples 1
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Companies House Examples
EXAMPLESecurity Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for Companies House — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 1
Portal, sign-up, and the first successful call
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 2
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 4
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 4
The organization behind the API
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/companies-house · machine-readable index on apis.io