Companies House API · Business Data · UK
Companies House API Integration.
Pull live company data directly into your platform — company status, registered addresses, director details, filing history and PSC data, straight from the official UK register. Fixed price. No per-search fees. Code you own outright.
Or describe what you need in one line — I’ll come back with a straight answer.
What it does
What the Companies House API provides.
The Companies House API is a free, official UK government API that gives programmatic access to the public register of UK companies. It returns company name, registration number, registered address, incorporation date, SIC codes, company status, officer details, persons with significant control (PSC), filing history and accounts documents.
A custom integration pulls that data directly into your website, CRM, internal system or onboarding workflow — automatically, in real time, without anyone running a manual search on the Companies House website.
The API itself is free. What costs money is building the integration correctly: authenticating securely, handling rate limits, mapping the response to your data model, surfacing the right fields in your UI, and writing the error handling that stops things breaking when a company number doesn’t exist or a request times out.
Why custom
Why a plugin won’t cut it.
There is no mainstream plugin for Companies House API integration because the use cases are always specific to the business using it. You might need company data to auto-populate a CRM field on form submission. Or to verify a supplier before approving an invoice. Or to flag when a client company changes director. Or to check company status before extending credit. None of those are the same integration.
Off-the-shelf compliance tools like SmartSearch or Veriphy bundle Companies House data into broader AML packages. They work well for standard onboarding. They do not work when you need the data inside your own system, your own UI, or your own workflow — without paying per-check fees forever. A custom integration is the right call when the use case is specific, the volume makes per-check pricing expensive, or the data needs to live inside your platform rather than a third-party dashboard. If you’ve considered scraping the Companies House website instead, read why the API is the right choice →
Official UK company data
Direct from the Companies House register — the same source accountants, lawyers and lenders use. Not scraped, not aggregated, not delayed.
Automated, not manual
Lookups triggered automatically by your workflow — form submission, CRM record creation, credit application — with no staff manually searching the Companies House website.
Free API, no per-search fees
The Companies House API has no usage fees. Once the integration is built, company lookups cost nothing beyond your hosting. No subscription, no per-check charge, no vendor lock-in.
Built into your platform
Data returned directly into your system — your CRM, your onboarding form, your internal admin panel. Not a third-party dashboard your team has to log into separately.
Who it’s for
Who uses a Companies House API integration.
Lenders and finance brokers
Credit decisions and KYB checks require verified company data. A custom integration pulls company status, incorporation date, registered address and director details directly into your loan application or credit assessment workflow — removing manual lookup steps and creating an auditable data trail without needing a full AML platform subscription.
Recruitment and staffing agencies
Verifying client companies before extending credit on placements is standard practice. But running manual Companies House searches on every new client is slow, inconsistently done, and creates gaps. An integration checks company status, directors and registered address automatically when a new client record is created in your CRM — flagging dissolved, struck-off or dormant companies before a placement goes ahead. How recruitment agencies use this integration →
Legal firms
Client onboarding in a legal context involves verifying the company, checking the right people have authority to instruct, and confirming the registered address. An integration can auto-populate your client intake form, surface director and PSC data for conflict-of-interest checks, and flag companies in administration or compulsory strike-off before a matter opens.
Property professionals and conveyancers
Commercial property transactions require company verification on the buyer or seller entity. An integration can pull registered address, company status and officer data into your case management system at the point a new matter is opened — reducing manual data entry and giving your team verified information from day one.
B2B SaaS with company-number-based signups
If your platform serves UK businesses and you collect a company name or number at signup, a Companies House integration can enrich that record automatically — pulling in the registered address, SIC code, incorporation date and director list without asking the user to fill it in manually. Cleaner data, less friction, more complete records.
The process
How a Companies House API integration is built.
Every integration is scoped before development starts, tested against real data and fully documented on handover.
Scoping
We establish which Companies House data fields you need, what triggers a lookup in your workflow, and how the response maps into your existing system or database.
Fixed-price quote
A clear, itemised quote before any work begins. Scope agreed in writing. No surprises mid-project.
API registration
Companies House developer hub registration and API key setup, with secure credential handling configured for your environment. Keys never exposed client-side.
Build and integration
Company search, officer lookup, PSC data, filing history or address verification built and wired into your platform to spec. Caching added where lookups repeat. Rate limiting and error handling included as standard.
Testing and handover
Full testing across company types and edge cases — dissolved, dormant, LLP, overseas. Complete technical documentation provided, covering the integration architecture, how to update API credentials, and how to extend the build if requirements change. The edge cases that catch people out →
The deliverable
What’s included.
Every integration is scoped, quoted at a fixed price and built to your exact requirements. You own the code outright.
What I build
- Companies House API registration and authentication
- Company search by name or registration number
- Officer and director detail retrieval
- PSC (persons with significant control) data
- Filing history retrieval with document links
- Registered address and company status lookup
- SIC code retrieval with plain-language descriptions
- Error handling for dissolved, dormant, LLP and overseas companies
- Caching layer to avoid repeat API calls
- Rate limiting for public-facing tools
- Technical handover document
What’s not included
- Structured financial data — accounts are available as filed PDFs only, not as queryable figures
- Real-time monitoring and change alerts — available in the Plus tier
- AML screening, sanctions checking or fraud scoring
- Ongoing retainer maintenance — available as an optional add-on
- Changes to your existing platform outside the defined integration scope
- Training sessions — documentation is provided; training available on request
Pricing
Fixed-price builds. No hidden costs.
Three tiers to match the scope of what you need. All prices are fixed and agreed before work starts. You own the code on final payment.
Starter
£1,495
~1 week
Single Companies House lookup integrated into one form, page or trigger point. Returns core company profile data. Best for basic company verification or CRM auto-population.
- Company search by name or number
- Core profile: name, number, status, address, incorporation date
- Error handling for invalid & dissolved companies
- Integration into one defined touchpoint
- Technical handover document
- Officer / director data
- PSC data
- Filing history
- Monitoring or alerts
Standard
£2,495
~2 weeks
Full company and officer lookup with admin interface, caching and complete error handling. Best for client onboarding, credit assessment, CRM enrichment and supplier verification.
- Everything in Starter
- Officer and director detail retrieval
- PSC (persons with significant control) data
- Filing history with document links
- SIC codes with plain-language descriptions
- Accounts & confirmation statement due dates with overdue flags
- Caching layer for repeat lookups
- Admin interface for lookup history
- Full error handling across all company types
- Technical handover document
Plus
£3,995
~3 weeks
Everything in Standard, plus ongoing monitoring with alerts when companies you track change status, director or file new documents. Best for ongoing KYB, credit risk and legal matter management.
- Everything in Standard
- Company watch list and monitoring layer
- Alerts on status changes — dissolution, administration, strike-off
- Alerts on director appointments and resignations
- Alerts on new filings — accounts, confirmation statements, charges
- Configurable notifications: email, webhook or internal
- Technical handover document
Payment terms: Projects £1,495–£2,495 — 50% on agreement, balance on completion before handover. Projects £3,995+ — 40% on agreement, 30% at mid-point, 30% on completion. Retainer monthly in advance. Code ownership transfers on final payment. — Full breakdown of what drives the cost →
See it in action
Try a live Companies House lookup.
Search any UK registered company and see exactly what the API returns — company profile, directors, filing history and PSC data, live from the official register. No login required.
Try the live demo →Common questions
Companies House API FAQ.
Is the Companies House API free?
Yes. The Companies House API is a free government resource — there are no per-search fees, no subscription and no usage limits beyond the standard rate limiting (600 requests per five minutes). The cost of a custom integration is for the development work, not the API access itself.
What data does the Companies House API return?
Company name, registration number, company status (active, dissolved, administration etc.), registered address, incorporation date, SIC codes, officer and director details, persons with significant control (PSC), filing history with document links, and accounts and confirmation statement information. It does not return financial accounts data as structured figures — filed accounts are available as PDF documents only.
Does it return financial accounts data?
Not as structured data. Filed accounts are available as PDF documents via the filing history endpoint, but the API does not return profit, turnover, assets or liabilities as queryable fields. If you need structured financial data, Companies House is not the source — credit reference agencies or financial data providers are a better fit.
Can it handle Scottish, Welsh and Northern Irish companies?
Yes. The Companies House register covers England, Wales, Scotland and Northern Ireland. Northern Ireland companies use a different registration number format (NI prefix) — the integration handles this correctly. Channel Islands and Isle of Man companies are not on the Companies House register and cannot be looked up via this API.
What if Companies House changes the API?
Companies House publishes advance notice of breaking API changes through their developer channels. If you’re on a retainer, API updates and endpoint changes are covered. If not, changes are quoted as a small fixed-price update — typically less than a day’s work for minor schema changes.
Does it work with my existing CRM or platform?
Yes, provided your CRM or platform has a way to receive data — a native API, a webhook endpoint, or a database the integration can write to. I’ve integrated with HubSpot, Salesforce, Xero, bespoke PHP and Node applications, and WordPress-based systems. If you tell me what your platform is built on, I’ll tell you how it connects.
Do I need a Companies House developer account?
Yes — Companies House requires an API key registered to a named person or organisation. I handle the registration as part of the project, set up secure credential management and document the process for you. The account is registered in your name so you’re never dependent on me for access.
How long does an integration take?
Starter builds typically take around one week. Standard builds take approximately two weeks. Plus builds with monitoring take around three weeks. Timeline starts once the project is scoped, the quote is agreed and the deposit is paid.
What happens if a lookup fails or a company number doesn’t exist?
Error handling is included as standard in every build. The integration returns appropriate error states for invalid company numbers, dissolved companies, companies not found, and API timeout or rate limit responses — rather than throwing unhandled errors to the end user.
Can you add Companies House lookups to a Shopify store?
Yes, via the Shopify Admin API or a custom app. This is typically relevant for B2B Shopify stores with a trade account application process — company verification at the point of account approval. Mention it when you get in touch and I’ll scope it specifically.
This sort of lookup is regularly built into Blackburn web design projects, and is most effective combined with Blackburn SEO services that bring qualified visitors to your site.
Need a Companies House integration built?
Describe your requirements — your platform, what triggers the lookup, and what you need to do with the data — and I’ll come back with a clear answer on what’s involved and what it costs. Fixed price, no obligation.
