> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thedatacity.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Company Matching API

> Match a company name to a UK Companies House registration number.

Send a company name (optionally with a website, postcode, SIC code, or trading date) and get back the best matching UK company registration number (CRN), plus the registered name and active status.

<Info>
  **This API is in beta.** It is stable enough to build against and serves production data. Keys are
  issued by hand — email [support@thedatacity.com](mailto:support@thedatacity.com) to get one.
  Feedback now shapes what ships next.
</Info>

## What you get back

| Field                        | What it is                                                             |
| ---------------------------- | ---------------------------------------------------------------------- |
| **matched\_company\_number** | Companies House registration number (CRN), when a match is found       |
| **matched\_company\_name**   | Registered name for that CRN                                           |
| **active**                   | Active / inactive (or equivalent) status from our company data         |
| **Request fields**           | Your `input_name`, optional `id`, URL, postcode, SIC, and trading date |

A single `POST /match` returns one result. For lists, submit a batch and poll until it completes, or pass `callback_url` to be notified once.

## Who it's for

Use this API when you need to attach a reliable Companies House identity to customer lists, CRM records, or enrichment pipelines.

## How to get started

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/company-matching/guides/quickstart">
    Get an API key and match your first company in a few minutes.
  </Card>

  <Card title="Authentication" icon="key" href="/company-matching/guides/authentication">
    Customer API keys (`dm_live_…`) as a Bearer token.
  </Card>

  <Card title="Response reference" icon="brackets-curly" href="/company-matching/guides/response-reference">
    Every field in the response, and when it is empty.
  </Card>

  <Card title="Batch matching" icon="layer-group" href="/company-matching/guides/batch">
    Submit up to 1,000 companies and poll for results.
  </Card>

  <Card title="Errors" icon="triangle-exclamation" href="/company-matching/guides/errors">
    Status codes, what they mean, and what to do.
  </Card>

  <Card title="Rate limits" icon="gauge-high" href="/company-matching/guides/rate-limits">
    Per-minute limits on match endpoints.
  </Card>
</CardGroup>

## Base URL

```text theme={null}
https://datamatcher-api.thedatacity.com/api/v1
```

All match endpoints sit under `/api/v1/match`. The interactive playground on each endpoint page lets you paste your API key and send live requests.

<Snippet file="need-help.mdx" />