# D2K Companies House Lookup

D2K Companies House Lookup brings the UK Companies House register into
Microsoft Dynamics 365 Business Central. You can look a company up by its registration number or its
name, keep the registered details on your customers and vendors in step with
the register, and have the app watch companies in the background and tell you
when they file something or change status.

It uses the free public Companies House API with your own API key, so the data
comes straight from the register and stays inside your tenant.

## Get started

1. [Set up Companies House Lookup](https://docs.d2k.uk/companies-house-lookup/companies-house-setup) - enter your API key
   and choose how long data is cached.
2. [Look up a company](https://docs.d2k.uk/companies-house-lookup/look-up-a-company) - by registration number or by name.
3. [Create a customer, vendor or contact from a company number](https://docs.d2k.uk/companies-house-lookup/create-from-companies-house).

## Everyday use

- [Customers, vendors and contacts](https://docs.d2k.uk/companies-house-lookup/customers-vendors-and-contacts) - link an
  existing record to the register, keep its name and address right, and see
  the company's status on the card.
- [Company snapshots](https://docs.d2k.uk/companies-house-lookup/company-snapshots) - what the app caches, how fresh it
  is, and how to refresh it.
- [Company officers](https://docs.d2k.uk/companies-house-lookup/company-officers) - who the directors are, and adding them
  as contacts.
- [Company filings](https://docs.d2k.uk/companies-house-lookup/company-filings) - what a company has filed, and
  downloading the document.
- [Filing watches](https://docs.d2k.uk/companies-house-lookup/filing-watches) - monitor companies in the background.
- [The Companies House Role Centre](https://docs.d2k.uk/companies-house-lookup/companies-house-role-centre) - what needs
  attention today.

## When something is wrong

- [Troubleshooting](https://docs.d2k.uk/companies-house-lookup/companies-house-troubleshooting) - errors, rate limits, API
  key problems and a stalled background poll.
- [Messages and what to do about them](https://docs.d2k.uk/companies-house-lookup/companies-house-messages) - every
  message the app shows, word for word, with the fix.

## What is new

- [Release notes](https://docs.d2k.uk/companies-house-lookup/release-notes) - what changed in each version.

## For developers

- [Building on D2K Companies House Lookup](https://docs.d2k.uk/companies-house-lookup/developers) - what is supported,
  the API, licensing and a worked example, for extensions that depend on the
  app.

## What it does not do

The app reads the public register. It never writes to Companies House, and it
holds no data from paid credit or business-information providers. Everything it
shows you is public information that anyone can look up at Companies House.

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Source: https://docs.d2k.uk/companies-house-lookup
Last updated: 2026-10-04