Where does the data come from?

From the official Dutch business register (KVK Handelsregister) and related authoritative sources. We collect, structure and keep it current so you always work with reliable data.

What is a KVK number?

A KVK number (KVK-nummer) is the unique 8-digit identifier the Dutch Chamber of Commerce assigns to every business registered in the Handelsregister. It identifies the legal entity as a whole. With Companize you can look up any Dutch company by its KVK number in a single API call.

What's the difference between a KVK number, an establishment number and an RSIN?

The KVK number (8 digits) identifies the registered business. An establishment number (vestigingsnummer, 12 digits) identifies one specific location of that business. The RSIN is the legal-entity identifier used by the Dutch Tax Authority. Every Companize profile returns all three where available.

SBI codes (Standaard Bedrijfsindeling) classify what a company actually does, its economic activity. Each profile returns the company's SBI activity codes, so you can filter, segment or enrich businesses by industry.

How do I look up a Dutch company by KVK number?

Call the lookup endpoint with the 8-digit KVK number and you get the full company profile back as JSON in one request: legal form, status, trade names, SBI activity codes, addresses and establishments. Don't know the number? Search by name first to find it.

Can I search by company name as well as KVK number?

Yes. You can run a full-text search by name and get ranked results, or look up an exact company by its KVK or establishment number.

Is KVK Handelsregister data public and free to use?

Yes. Company information in the Handelsregister is public by law, so you don't need a company's permission to look it up. Companize doesn't charge for the public facts themselves; you pay for the convenience of a fast, structured, always-current API instead of scraping the register yourself.

How fresh is the data?

We sync continuously with the source. New registrations and changes are reflected automatically, so you never have to re-scrape or maintain your own pipeline.

Can I use this for KYC, onboarding or enriching a list of companies?

Yes. Authoritative register data is ideal for KYC, customer onboarding, credit checks and keeping a CRM clean. Look companies up one by one or enrich a list by name or KVK number, and get a consistent structured profile back every time.

How is this different from the official KVK API?

Companize gives you one clean REST endpoint, JSON everywhere, full-text search, typo tolerance and predictable latency, without managing scrapers or stitching sources together. We keep the data in sync with the official register, so you get authoritative data with a developer-friendly experience.

Is this allowed under GDPR?

Most register data describes legal entities, which falls outside GDPR. Some records (such as sole proprietorships) can include personal data, and there you remain the controller for how you use it in your own application. We only serve what the register publishes openly; lawful use within your product is your responsibility.

We're finalising pricing for launch, with a free tier to start building and usage-based plans as you grow. Join the waitlist and we'll share details beforehand.

We're onboarding early users from the waitlist now. Add your email and you'll be among the first to get access and an API key.

Now in private beta. Join the waitlist.

Every Dutch company, one API call away.

Companize turns the Dutch Chamber of Commerce (KVK) register into a fast, modern API. Search by name or KVK number and get the full business profile back as clean JSON. In milliseconds.

Join the waitlist Explore the API

Search by name or KVK number

Complete profiles as JSON

No scraping, no maintenance

GET /v1/companies/69599084 200 OK

{
  "kvk_number": "69599084",
  "name": "Coolblue B.V.",
  "legal_form": "Besloten vennootschap",
  "status": "active",
  "trade_names": ["Coolblue"],
  "sbi_activities": [
    { "code": "4791", "description": "Retail via internet" }
  ],
  "establishment": {
    "establishment_number": "000019625863",
    "founded_on": "1999-05-31",
    "employees": 2500
  },
  "visiting_address": {
    "street": "Weena 664",
    "postal_code": "3012 CN",
    "city": "Rotterdam"
  }
}

Built on authoritative Dutch business sources

KVK Handelsregister SBI activity codes RSIN & VAT identifiers Dutch postal address data

Why developers choose us

The fastest way to work with Dutch company data

Companize does the hard part: collecting, structuring and keeping company data current. You ship features instead of maintaining scrapers.

Search by name or KVK number: Full-text search across millions of Dutch companies, or look up an exact match by KVK or establishment number. Typo-tolerant and ranked by relevance.
Complete business profiles: Everything from the register in one structured response: legal form, status, trade names, activities, addresses and establishments.
Always up to date: We sync continuously with the source, so you never serve stale data or have to re-scrape. New registrations and changes flow through automatically.
Built for speed: A purpose-built index returns results in milliseconds, with predictable latency you can build real-time experiences on top of.
Developer-first: A clean REST API, JSON everywhere, API keys you manage yourself, sensible pagination and clear docs. Integrate in minutes.
Compliance-ready: Authoritative data straight from the official register. Ideal for KYC, onboarding, credit checks and keeping your CRM clean.

Complete coverage

All the business data you need

Every company profile comes fully structured and ready to use; no parsing HTML, no piecing fields together from different sources.

One consistent schema across every company, whether it's a one-person business or a multinational with hundreds of establishments.

Company & trade names
KVK number
Establishment number
RSIN identifier
Legal form
Registration status
SBI activity codes
Founding date
Visiting address
Postal address
Establishments
Employee count

Developer experience

A REST API you'll enjoy using

Authenticate with a bearer token, call a single endpoint, get JSON. That's it.

Search companies

Find companies by name, with relevance ranking and pagination.

GET /v1/companies?q=coolblue

curl https://api.companize.com/v1/companies \
  -G --data-urlencode "q=coolblue" \
  -H "Authorization: Bearer $API_KEY"

Look up a company

Fetch a complete profile by KVK number in a single request.

GET /v1/companies/69599084

curl https://api.companize.com/v1/companies/69599084 \
  -H "Authorization: Bearer $API_KEY"

Coverage you can build a business on

The whole Dutch register, kept current and served fast.

Companies indexed: 3.8M+
Fields per company: 40+
Median response time: <100ms
Uptime target: 99.9%

Frequently asked questions

: From the official Dutch business register (KVK Handelsregister) and related authoritative sources. We collect, structure and keep it current so you always work with reliable data.
: A KVK number (KVK-nummer) is the unique 8-digit identifier the Dutch Chamber of Commerce assigns to every business registered in the Handelsregister. It identifies the legal entity as a whole. With Companize you can look up any Dutch company by its KVK number in a single API call.
: The KVK number (8 digits) identifies the registered business. An establishment number (vestigingsnummer, 12 digits) identifies one specific location of that business. The RSIN is the legal-entity identifier used by the Dutch Tax Authority. Every Companize profile returns all three where available.
: SBI codes (Standaard Bedrijfsindeling) classify what a company actually does, its economic activity. Each profile returns the company's SBI activity codes, so you can filter, segment or enrich businesses by industry.
: Call the lookup endpoint with the 8-digit KVK number and you get the full company profile back as JSON in one request: legal form, status, trade names, SBI activity codes, addresses and establishments. Don't know the number? Search by name first to find it.
: Yes. You can run a full-text search by name and get ranked results, or look up an exact company by its KVK or establishment number.
: Yes. Company information in the Handelsregister is public by law, so you don't need a company's permission to look it up. Companize doesn't charge for the public facts themselves; you pay for the convenience of a fast, structured, always-current API instead of scraping the register yourself.
: We sync continuously with the source. New registrations and changes are reflected automatically, so you never have to re-scrape or maintain your own pipeline.
: Yes. Authoritative register data is ideal for KYC, customer onboarding, credit checks and keeping a CRM clean. Look companies up one by one or enrich a list by name or KVK number, and get a consistent structured profile back every time.
: Companize gives you one clean REST endpoint, JSON everywhere, full-text search, typo tolerance and predictable latency, without managing scrapers or stitching sources together. We keep the data in sync with the official register, so you get authoritative data with a developer-friendly experience.
: Most register data describes legal entities, which falls outside GDPR. Some records (such as sole proprietorships) can include personal data, and there you remain the controller for how you use it in your own application. We only serve what the register publishes openly; lawful use within your product is your responsibility.
: We're finalising pricing for launch, with a free tier to start building and usage-based plans as you grow. Join the waitlist and we'll share details beforehand.
: We're onboarding early users from the waitlist now. Add your email and you'll be among the first to get access and an API key.

Be first to build on Companize

Join the waitlist for early access, a free tier at launch and updates as we roll out. No spam, just the important stuff.

We'll only use your email to contact you about early access. Unsubscribe anytime.