Austrian company register API: company data as JSON

Register number in, company data out: name, seat, legal form, status, the list of annual accounts and, with a subscription, balance sheet and P&L in cents. As a REST API for your CRM and as an MCP server for AI assistants.

Create a key Pricing

Four endpoints, one key

Request	Response
`GET /api/v1/companies?q=Muster`	Search by name, up to 25 hits (at least three characters)
`GET /api/v1/companies/{fnr}`	Company data: name, seat, legal form, status, list of annual accounts, insolvency notices
`GET /api/v1/companies/{fnr}/financials?load=1`	Balance sheet and P&L per year in cents, unchanged, plus our ratios; load=1 loads one more year
`GET /api/v1/companies/{fnr}/documents/{stichtag}`	The annual accounts as a PDF, as filed

The key starts with fbd_ and goes into the header Authorization: Bearer. We store only its SHA-256 hash and show it once. Every response names the source.

Example

curl -H "Authorization: Bearer fbd_…" https://firmenbuchdaten.at/api/v1/companies/999999m

{
  "fnr": "999999m",
  "name": "Muster Handels GmbH",
  "sitz": "Linz",
  "rechtsform": "Gesellschaft mit beschränkter Haftung",
  "status": "eingetragen",
  "soleTrader": false,
  "annualAccounts": [
    { "stichtag": "2024-12-31", "sizeClass": "K", "filed": "2025-08-27", "formats": ["PDF"] }
  ],
  "lastChange": "2026-03-12",
  "insolvencyNotices": [],
  "retrievedAt": "2026-11-02T06:14:09Z",
  "source": "Österreichisches Firmenbuch, Republik Österreich, vertreten durch das BMJ, offene Daten unter CC BY 4.0"
}

A made-up company. The size class is the register's letter (W, K, M, G), lastChange the latest entry date.

MCP for AI assistants

The MCP server speaks Streamable HTTP at /mcp and has three tools: search_companies, get_company and get_financials. Your assistant finds a company, reads the latest accounts and works with real figures instead of memories.

{
  "mcpServers": {
    "firmenbuchdaten": {
      "type": "http",
      "url": "https://firmenbuchdaten.at/mcp",
      "headers": { "Authorization": "Bearer fbd_…" }
    }
  }
}

Calls per plan

	Free	Pro	Business
Calls	1 per week	1 per week	1,000 per month
Company data and search	✓	✓	✓
Balance sheet, P&L and ratios	only the company of your free query	✓	✓
Annual accounts as PDF	–	✓ (20 per hour)	✓ (20 per hour)
Price	free	€19.99 per month	€49.99 per month

Prices net plus VAT, cancel monthly. Every request costs one call, search included. When the quota is used up, the API answers 429.

Errors worth knowing

400 invalid register number, for example a wrong check letter
401 key missing or revoked
403 plan_without_financials figures come with Pro or Business
404 no such register number
429 quota for this week or month used up
503 register_busy register paused, try again later

Frequently asked questions

Does the API return persons?

No. Managing directors, shareholders and other persons are not available through the API, MCP or CSV. Sole traders are marked with soleTrader so you can leave them out.

Where does the data come from?

From the Austrian company register, open data of the Republic of Austria (Federal Ministry of Justice) under CC BY 4.0. Register content stays unchanged; ratios are marked as our evaluation. Name the source when you show the data.

What happens when the register is busy?

Companies we already hold are answered from our database. A company we have never loaded needs the register; if it is paused, the API answers 503 register_busy and you try again later.

Can I use it in ChatGPT, Claude or Cursor?

Yes, through the MCP server at /mcp with the same key. Each tool call costs one credit, like a REST call.

Read on

Source: Austrian company register (Firmenbuch), Republic of Austria, represented by the BMJ, open data under CC BY 4.0.