EU Business & VAT Checker in ChatGPT

Questions it answers

Validate an EU VAT number on VIES, look up an LEI, or search a company register. Ask "is ES A28015865 a valid VAT number?", "what is the LEI of Siemens AG?" or "find the registered company called Equinor in Norway".

EU Business and VAT Checker asks the official sources directly: the European Commission's VIES service for VAT numbers, the GLEIF Global LEI Index for Legal Entity Identifiers, and two national registers, the French Sirene register (through the api.gouv.fr company search) and the Norwegian Enhetsregisteret. People also call it EU Business Check.

Use it to validate a VAT number or a tax identification number before a reverse-charge invoice, or as the register step of a vendor onboarding or KYB check. It does not calculate the reverse charge and it does not score credit. It does not say whether a seller must register for VAT or at which rate. The French registration number on a Kbis extract is the SIREN; this tool returns that register record, not the extract itself.

A VAT check says whether a number is registered for VAT in an EU member state or Northern Ireland on the day of the check. When the registered name and address are published they are shown, but only for legal entities: a name without a legal-form marker such as GmbH, SA, SRL or Limited could be a private person, so it is withheld. Some countries, such as Germany and Spain, do not publish a name at all. If you give your own VAT number, VIES also issues a consultation number that proves the check was made.

LEI and registry results show the legal name, status, legal form, registration number, address and, where published, activity and size. Sole proprietors are left out of every result because they are registered under a private person's name.

Given a company's domain, such as stripe.com, company_from_domain returns the legal name, the country, the registration number, a size band and the age of the company, each with a source link, the day it was read and how sure the match is. It reads the company's own legal pages where robots.txt allows it, Wikidata, the registers above, GLEIF and SEC EDGAR, and it says which facts it could not find. It is for companies only: an email address from a free mail provider or a free subdomain gives no company, and no person is ever named.

It reads only public sources: these registers, Wikidata, SEC EDGAR, the registry record of a domain name, and a company's own pages where robots.txt allows it. It does not rate a company's credit, solvency or reputation, does not cover other countries' registers (a company outside France and Norway is named from GLEIF, SEC EDGAR, Wikidata or its own pages, so its size and age may be unknown), and a register can lag behind a change by days. Always check an important detail on the register itself.

It keeps no account or profile of you: answers are cached for up to an hour (six hours for a domain lookup), except a check that asks for a consultation number; the arguments of each call are kept for 14 days in a cleaned input log, with an email address replaced by [email]; and the other lasting records are a daily count of calls per tool and a daily count of domain lookups per network, kept without the domain or the address.

Short questions this server answers, each with a direct answer: Check EU VAT numbers, LEIs and company registers.

What it can do

• Returns the legal name, country, registration number, size band and age behind a company domain, each with a source link
• Validates an EU or Northern Ireland VAT number on VIES and shows the name of a legal entity
• Issues a VIES consultation number when given the requester's own VAT number
• Finds the Legal Entity Identifier (LEI) of a company by name, or looks a LEI up
• Searches the French Sirene register by SIREN and the Norwegian company register by name or number
• Leaves out sole proprietors and withholds names that could be a private person

Tools

• company_from_domain, Find the company behind a domain. Use this when the user has a company domain, a website or a work email address and wants to know the company behind it, for example "which company is behind doctolib.fr?", "how big and how old is the company at stripe.com?" or "who is the legal entity for the lead that wrote from jane@acme.io?". Pass the domain. Returns the legal name, country, registration number, a size band and the age of the company, each with a source link, the day it was read and a confidence of confirmed, name_match, printed_on_site or wikidata_only. A fact that could not be found is listed under unknown with the reason, never guessed. Companies only: free mail providers and free subdomains give no company, sole proprietors are left out, and no person, owner or employee is named. Do not use it for a person, for credit or risk, or for a company that has no public record.
• check_vat_number, Validate an EU VAT number on VIES. Use this when the user asks to validate a VAT number, check a tax ID or get a VIES consultation number, for example "is ES A28015865 a valid VAT number?". Pass country as a two-letter code (Greece is EL) or English name, and vatNumber as printed, with or without its prefix, spaces, dots or dashes, for example {"country":"DE","vatNumber":"DE 811 128 135"}. A prefix that names another country is refused. Send requesterCountry and requesterVatNumber only when the user gives their own business VAT number, for a consultation number. Returns whether the number is registered for VAT on the date of the check and, where published, the company name and address. Covers EU member states and Northern Ireland (XI), not GB. Do not use it for VAT rates or to judge whether a business is trustworthy.
• find_company_lei, Look up a Legal Entity Identifier. Use this when the user asks for the Legal Entity Identifier (LEI) of a company, including a KYB or vendor onboarding check, for example "what is the LEI of Siemens AG?", "whose LEI is W38RGI023J3WT1HWRP32?" or "is the LEI of this German company still active?". Pass the company name (and a country code to narrow it) or the 20-character LEI. Returns each entity's LEI, legal name, status, legal form code, country and city, national registration number and the LEI's renewal dates. Sole proprietors are left out. Do not use it to find a private person, for companies that have no LEI (most small businesses), or for financial or credit information.
• lookup_company_registry, Search a French SIREN or Norwegian register. Use this when the user asks about a company registered in France or Norway, or for the company registration number on a Kbis extract, for example "find the French company Danone", "who is behind SIREN 552032534?" or "look up Equinor in the Norwegian business register". Pass country FR or NO and the company name or its registration number (SIREN for France, organisation number for Norway). Returns the legal name, registration number, legal form, status (active, ceased, bankrupt, being wound up), registration date, registered address, activity code and, where published, size or employee count. Sole proprietors are left out. Do not use it for other countries, for owners, directors or any private person, or for accounts and credit ratings.

Add EU Business & VAT Checker in ChatGPT

ChatGPT does not read a local config file. A custom MCP server is added in the product, and only after developer mode is on. These steps were checked against OpenAI's plugin connect guide and the ChatGPT MCP guide on 2026-10-01. Developer mode can be hidden by a workspace policy, so a Team or Enterprise admin may have to allow it first.

1. Open ChatGPT settings, then Security and login, and turn on Developer mode.
2. Open ChatGPT plugins and select the plus button.
3. Enter a name such as "EU Business & VAT Checker" and a one-line description of what you want it to answer.
4. Under Connection, choose the public endpoint and paste this URL. Include the /mcp path. Do not add a tunnel id: this server is already public.

   https://eubusiness.openkrill.app/mcp

5. Create the connection and review the tools ChatGPT lists. You should see company_from_domain, check_vat_number, find_company_lei, lookup_company_registry. The feedback tools on the same server are optional and not required for the lookup.
6. Start a new conversation, add the connection from the tools menu, and ask: Which company is behind the domain doctolib.fr, and how big is it?

No API key and no OAuth client id are required. The server answers without a login. Calls are limited per network and per day, and a limit comes back as a tool error rather than a partial answer. If the tool list is stale after a server change, open the connection and select Refresh, then start a new conversation.

The ChatGPT desktop app, Codex CLI and IDE extension share a different config. In the desktop app, open Settings, then MCP servers, choose Add server, select Streamable HTTP, and paste the same URL. In ~/.codex/config.toml the equivalent is a table named mcp_servers.eu-business with url = "https://eubusiness.openkrill.app/mcp". ChatGPT on the web does not read that file. A published directory listing is also a different path: this page is the developer-mode connection, not a claim that EU Business & VAT Checker is already in the ChatGPT directory.

Treat the server as untrusted until you have read a few answers. A remote MCP server sees the arguments the model sends. EU Business & VAT Checker is read-only and documents what it sends onward on the privacy page.

If it does not work

A call checked on 2026-10-17

ATU33864707 is the public example in the plugin's starter prompts. No requester VAT number is sent. The request below was posted to https://eubusiness.openkrill.app/mcp as tools/call. HTTP 200. Source: the EU Business & VAT Checker server, read 2026-10-17.

{
  "method": "tools/call",
  "params": {
    "name": "check_vat_number",
    "arguments": {
      "country": "AT",
      "vatNumber": "U33864707"
    }
  }
}

• source. European Commission VIES (VAT Information Exchange System)
• country. AT
• name. Red Bull GmbH
• notice. A valid result means the number is registered for VAT in that member state, as the member state's own register reports it on the date shown. It does not say the business is trustworthy, solvent or the one a person is dea

Repeat the call yourself if you need a newer reading. Cached answers expire. A rate limit is not a result: wait and try again. Nothing in the call is a ranking, a filing, or advice.

Using it in production

Nothing to install and nothing to run: no package, no Python or Node.js version and no environment variable. EU Business & VAT Checker runs on our servers, and your client only needs the URL https://eubusiness.openkrill.app/mcp.

Use it in other apps

• EU Business & VAT Checker in Claude
• EU Business & VAT Checker in Cursor
• EU Business & VAT Checker in VS Code
• EU Business & VAT Checker in Pi

Roles that use EU Business & VAT Checker

• Importer guide
• Compliance reader guide

Frequently asked questions

Words on this page

• MCP (Model Context Protocol) definition
• Streamable HTTP transport definition
• Tool primitive definition
• Rate limit policy definition

Source: plugin listing for eu-business in this repository, and a live tools/call on 2026-10-17. As of 2026-10-17.