# Tax ID Format Check (EIN, VAT, SIREN) > Check whether a tax ID or TIN is the right shape for its country, for the countries we already validate. Canonical: https://corpoapi.com/checks/tax-id-lookup Pick the country and the type of number, type it, and the check reports whether it is well formed. It runs the same format rules the rest of the site uses, so it never claims coverage we do not have. ## What the check reads - **The country and type** You choose which rule runs, so a US number is never checked against a Swedish rule. The set is fixed to the countries we already validate. - **United States, EIN or TIN** Nine digits, with the first two inside the ranges the tax authority assigns. A number with letters, or the wrong number of digits, is rejected. - **European Union, VAT number** A two-letter country prefix followed by 2 to 13 characters, and the prefix must be one the European VAT register covers. A UK number is named as out of scope. - **Sweden, organisationsnummer** Ten digits with a Luhn check digit, often written with a hyphen before the last four. - **France, SIREN** Nine digits with a Luhn check digit. A SIRET adds five digits for one establishment and is not accepted here. - **What is not checked** Whether the number was ever issued, whether the business still trades, and whether it belongs to the company on your invoice. None of that is a format question. ## Where the data comes from - [US tax authority: valid EIN prefixes](https://www.irs.gov/businesses/small-businesses-self-employed/valid-eins): The ranges the EIN option checks the first two digits against. - [the official VAT register](https://ec.europa.eu/taxation_customs/vies/): The member states the VAT option covers, plus Northern Ireland as XI. ## Worked examples ### A nine-digit US number with an assigned prefix Input: `12-3456789, US EIN or TIN` - **Type**: US EIN or TIN - **Nine digits**: Yes - **Prefix 12 assigned**: Yes - **Verdict**: Well formed A format example, not a real taxpayer. It shows the shape passing, not that any particular EIN was issued. ### A VAT number the European register covers Input: `SE556029519701, EU VAT number` - **Type**: EU VAT number - **Country prefix**: SE, covered - **Length**: Valid - **Verdict**: Well formed The prefix decides coverage. Sweden is covered; a UK number is not. ### A UK number, out of scope rather than wrong Input: `GB123456789, EU VAT number` - **Type**: EU VAT number - **Country prefix**: GB, not covered - **Verdict**: Out of scope The European VAT register no longer covers the United Kingdom. Northern Ireland is still covered, under the XI prefix. ## The shape of the number, by country A tax ID is not one format. A US EIN is nine digits with an assigned prefix, an EU VAT number carries a two-letter country prefix, a Swedish organisationsnummer ends in a check digit and a French SIREN does the same. Each option here runs that country's own rule, the one the API applies elsewhere. - A fixed set of countries and number types - The same rule the dedicated tool already uses - Names the failing part instead of a bare rejection ## What a US TIN check covers In the United States a business taxpayer identification number is the EIN, nine digits written with a hyphen after the first two. The first two are a code for the tax office that issued it, and only certain ranges are assigned. A well-formed number with an assigned prefix is one the tax authority could have issued. Nothing public joins it to a company. - Nine digits, hyphen optional - The first two digits checked against the assigned ranges - Single member and other EIN variants share the same nine-digit shape ## A format match is not a business Every option here checks shape only. A number can be well formed and still never have been issued, and a tax ID does not map to a company in any public register we can read. When you need the business behind a number, search the company register by name instead. - A well-formed number does not identify a business - Registration status lives in the company register - The free company search resolves a name to an entity ## FAQ ### What is a TIN? A taxpayer identification number, the general name for the number a tax authority issues to a person or a business. In the United States a business TIN is the EIN, nine digits. This tool checks the US EIN shape and, separately, the VAT and company numbers other countries use. ### Does a valid tax ID prove the business exists? No. These are format checks. A well-formed number may never have been issued, and a tax ID does not map to a company in any public register we can read. To confirm a business, search the company register by name and status. ### Which countries does the format check cover? Only the four we already validate: the United States (EIN or TIN), the European Union (VAT number), Sweden (organisationsnummer) and France (SIREN). We list only what we can check honestly, and we add a country when its rule is real, not before. ### Why is a UK VAT number out of scope? The European VAT register stopped covering the United Kingdom after Brexit. Only Northern Ireland, under the XI prefix, is still answered by that service. A UK VAT number is checked with the UK tax authority instead, which is a different register. ### Is a tax ID the same as an EIN? In the United States, for a business, yes. EIN stands for employer identification number, and it is the business taxpayer identification number. An ITIN and an SSN share the nine-digit shape but belong to individuals, and this check is written for the business number. ### Can I look up the company behind a tax ID? Not from a tax ID alone. The registers we read publish a company number, not a tax ID, and nothing public joins the two. Try the free company search with the trading name and the state or country, then confirm the match by number.