VAT API

API Credit Usage

You need to login or signup to use the BuiltWith API. After logging in your actual API key will be shown here.

Introduction

The VAT API returns VAT, GSTIN, CNPJ, ABN and other available company registration numbers for websites.

This is particularly useful for products that accept business signups or payments and need company registration details to help determine how tax should be charged. For example, a billing or checkout workflow can look up the domain from a customer's business email or website, identify an available VAT or local registration number, and use it to pre-fill tax fields, reduce signup friction, flag accounts for tax review, or support business-to-business tax handling.

The data can also help enrich customer records, distinguish businesses from consumers, reconcile company details, and prioritize cases where registration information should be confirmed. Registration data should be verified with the appropriate official tax authority before it is relied upon for tax calculation, exemption, invoicing, or compliance decisions.

Each domain that returns one or more registration records uses one API credit. Domains with no registration results do not use a credit. You can look up between 1 and 16 comma-separated root domains in one request.

Authentication

You must provide your API key in each lookup. Our endpoints are HTTPS only, providing key encryption. Never expose your API key.

Your API Key is
00000000-0000-0000-0000-000000000000

You can supply your key as a query string parameter or as an HTTP header:

Query string: ?KEY=00000000-0000-0000-0000-000000000000
HTTP header: Authorization: API 00000000-0000-0000-0000-000000000000

Working Examples

JSON Get company registration numbers for BuiltWith
https://api.builtwith.com/vat1/api.json?KEY=00000000-0000-0000-0000-000000000000&LOOKUP=builtwith.com

XML Get company registration numbers for BuiltWith
https://api.builtwith.com/vat1/api.xml?KEY=00000000-0000-0000-0000-000000000000&LOOKUP=builtwith.com

CSV Get company registration numbers for BuiltWith
https://api.builtwith.com/vat1/api.csv?KEY=00000000-0000-0000-0000-000000000000&LOOKUP=builtwith.com

JSON Get company registration numbers for multiple domains
https://api.builtwith.com/vat1/api.json?KEY=00000000-0000-0000-0000-000000000000&LOOKUP=example.com,builtwith.com

Response

Results are flat records containing Domain, Type and Number. A domain can return more than one record. Domains without known registration data return no records.

[ { "Domain": "builtwith.com", "Type": "GSTIN", "Number": "2332323" } ]

CSV responses contain the same values:

Domain,Type,Number builtwith.com,GSTIN,2332323

Company Registration Types

The public registration-types endpoint lists every value that may appear in the VAT API Type field, together with its friendly name and description. It does not require an API key or use API credits.

https://api.builtwith.com/vat1/types.json

XML and CSV are also available at /vat1/types.xml and /vat1/types.csv.

Type	Name	Description
`ABN`	ABN	Australian Business Number issued by the ATO, an 11-digit identifier for entities carrying on business in Australia.
`ACN`	ACN	Australian Company Number issued by ASIC, a 9-digit identifier assigned to every registered Australian company.
`AFM`	AFM	Greek tax registration number (Arithmos Forologikou Mitroou), a 9-digit identifier assigned by the tax authority.
`BCE`	BCE	Belgian Crossroads Bank for Enterprises number, a 10-digit identifier for companies registered in Belgium.
`BN`	Business No.	Canadian Business Number issued by the CRA, a 9-digit identifier that may include a 4-digit program account suffix.
`BRN`	Business Reg. No.	South Korean Business Registration Number issued by the NTS, formatted as XXX-XX-XXXXX.
`CEGJEGYZEKSZAM`	Company Reg. No.	Hungarian company registration number (Cégjegyzékszám) held in the company register, formatted as XX-XX-XXXXXX.
`CIF`	CIF	Spanish tax identification number (Código de Identificación Fiscal) for legal entities, beginning with a letter followed by 8 alphanumeric characters.
`CIN`	CIN	Indian Corporate Identity Number issued by the MCA, a 21-character alphanumeric code identifying every registered company.
`CNPJ`	CNPJ	Brazilian company registration number (Cadastro Nacional da Pessoa Jurídica) issued by the Receita Federal, consisting of 14 digits.
`CRN`	Company Reg. No.	UK Companies House registration number, typically 5–8 digits with an optional prefix such as SC (Scotland) or NI (Northern Ireland).
`CRO`	CRO No.	Irish Companies Registration Office number, a 5–6 digit identifier assigned to companies registered in Ireland.
`CUI`	CUI	Romanian Unique Registration Code (Cod Unic de Înregistrare), a fiscal identifier prefixed with RO assigned to companies by the tax authority.
`CVR`	CVR	Danish Central Business Register number (CVR-nummer), an 8-digit identifier for all registered businesses in Denmark.
`DIC`	DIC	Czech or Slovak tax identification number (Daňové identifikační číslo), an 8–10 digit code optionally prefixed with a country code.
`EIN`	EIN	US Employer Identification Number issued by the IRS, formatted as XX-XXXXXXX and used for federal tax purposes.
`FBN`	FBN	Austrian commercial register number (Firmenbuchnummer), consisting of 4–6 digits followed by a check letter.
`GEMI`	GEMI	Greek General Electronic Commercial Registry number (ΓΕΜΗ), an 8–12 digit identifier for companies registered in Greece.
`GSTIN`	GSTIN	Indian Goods and Services Tax Identification Number, a 15-character alphanumeric code linking a business to its GST obligations.
`HRB`	HRB	German commercial register number (Handelsregisternummer), consisting of a HR prefix, letter, and number recorded at the local court.
`ICO`	ICO	Czech or Slovak company identification number (Identifikační číslo osoby), an 8-digit code assigned by the business register.
`JP_CORPORATE_NUMBER`	JP Corporate No.	Japanese corporate number (法人番号), a 13-digit identifier assigned by the National Tax Agency to every registered legal entity.
`KRS`	KRS	Polish National Court Register number (Krajowy Rejestr Sądowy), a 10-digit identifier for companies registered in Poland.
`KVK`	KVK	Dutch Chamber of Commerce number (Kamer van Koophandel), an 8-digit identifier assigned to businesses registered in the Netherlands.
`NIP`	NIP	Polish tax identification number (Numer Identyfikacji Podatkowej), a 10-digit code used for tax and VAT purposes.
`NIPC`	NIPC	Portuguese company tax identification number (Número de Identificação de Pessoa Coletiva), a 9-digit code assigned by the tax authority.
`ORGNR`	Org. No.	Scandinavian organisation number used in Sweden (6+4 digits) and Norway (9 digits) to identify registered legal entities.
`PIVA`	P. IVA	Italian VAT number (Partita IVA), an 11-digit identifier assigned to businesses liable for VAT in Italy.
`RCS`	RCS	Luxembourg Trade and Companies Register number (Registre de Commerce et des Sociétés), beginning with a letter followed by up to 6 digits.
`REGCOM`	Reg. Com.	Romanian Trade Register number in J-format (e.g. J40/1234/2000), identifying the county, sequence, and year of registration.
`REGON`	REGON	Polish statistical identification number (Rejestr Gospodarki Narodowej), either 9 or 14 digits, assigned by the Central Statistical Office.
`RFC`	RFC	Mexican Federal Taxpayer Registry code (Registro Federal de Contribuyentes), a 12–13 character alphanumeric identifier for tax purposes.
`SIREN`	SIREN	French company identifier (Système d'Identification du Répertoire des ENtreprises), a 9-digit code assigned by INSEE.
`SIRET`	SIRET	French business location identifier (Système d'Identification du Répertoire des ETablissements), a 14-digit code extending the SIREN with an establishment suffix.
`UID`	UID	Swiss or Austrian company identification number; Swiss UIDs are prefixed CHE with 9 digits, Austrian UIDs are prefixed ATU with 8 digits.
`USCC`	USCC	Chinese Unified Social Credit Code (统一社会信用代码), an 18-character alphanumeric identifier assigned to all registered organisations.
`USTID`	USt-IdNr.	German VAT identification number (Umsatzsteuer-Identifikationsnummer), formatted as DE followed by 9 digits.
`VAT`	VAT	European-style VAT registration number consisting of a 2-letter country prefix followed by up to 18 alphanumeric characters.
`YTUNNUS`	Y-tunnus	Finnish Business ID (Y-tunnus), a 7-digit number followed by a hyphen and a check digit, assigned by the PRH.

API Reference

KEY (required): your BuiltWith API key.
LOOKUP (required): 1 to 16 comma-separated domains.
Formats: json, xml, and csv.
Credit cost: 1 API credit per domain that returns at least one registration record; no credit is used when a domain returns no results.

Special Domains

We maintain two lists of use for you when looking up domains. Ignore lists and BuiltWith Suffix lists.

Ignore List
This is our own internal list of domains we do not index. They are either blocked, contains too many misleading technologies or too many subdomains with user generated content.

BuiltWith Suffix List
This is based on the Public Suffix List but includes many additional entries for companies with subdomains that should be considered top level domains. This list provides us with better visibility for internal websites for example it brings northernbeaches.nsw.gov.au to the top level over nsw.gov.au.

Ignore Domains (XML, JSON or TXT)

https://api.builtwith.com/ignoresv1/api.json

Suffix Domains (XML, JSON or TXT)

https://api.builtwith.com/suffixv1/api.json

Error Codes

Note error messages in this format cannot be guaranteed, your implementation should also consider non-200 response codes as errors. The Lookup property will be null (json) or not provided (xml) if the error is server related. View all potential well-formed error codes.

Our standard terms cover the use all of our APIs.

In general, you can use the API to enhance your product in many ways. The only limitation is you cannot resell the data as-is or provide duplicate functionality to builtwith.com and its associated services.