A chamber of commerce number is the unique registration number a business receives when it is entered in the national business register. In the Netherlands this is the KvK number, an eight-digit number issued by the Kamer van Koophandel, and it identifies your business in every official context: on invoices, in contracts and in the public register. In this article you can read what the number means, where to find it, how it differs from your VAT number and RSIN, and the mistakes that most often cause confusion.
Which number is this, exactly? This article covers the Dutch KvK number, also written as CoC number or CCI number in English-language documents. Every EU country has an equivalent, but the name, the length and the issuing body differ per country, so a number from one register is not interchangeable with another. And note: your chamber of commerce number is not your VAT number, and it is not the phone number of a chamber of commerce office.
Looking for something more specific? If you still have to register your business, read about registering at the chamber of commerce. If it is your VAT number you need, see where to find your VAT number or how to look up someone else’s. And if you want the formats side by side, go to the comparison table.
Table of contents
What is a chamber of commerce number?
The number is your business’s identifier in the national register of companies. In the Netherlands you receive it the moment your registration with the Kamer van Koophandel is completed, and it stays with your business for as long as it exists. It does not change when you move premises, change your trade name or take on staff. That permanence is the point: anyone who has your number can find out who they are dealing with, years later.
Where do you find your KvK number?
- On your registration extract (uittreksel), the document you received when you registered.
- In the public register, searchable by company name on the KvK website.
- On your own invoices and letterhead, where it has to be stated.
- In your accounting software, under your company details.
Looking for a supplier’s or customer’s number rather than your own? The register is public, so searching on the company name is usually enough. That is also how you check that the business on an invoice is the business you think it is.
KvK number, RSIN and VAT number compared
| Number | Format | Used for |
| KvK number (CoC number) | 8 digits, e.g. 12345678 | Identifying your business in the register, on invoices and in contracts |
| RSIN | 9 digits | Legal entities such as a BV or foundation, used between government bodies |
| VAT identification number | NL + 9 digits + B + 2 digits, e.g. NL001234567B01 | VAT: invoicing, returns, reverse charge and VIES checks |
The confusion almost always sits between the first and the last row. Both identify your business, but they answer different questions: the KvK number says who you are, the VAT number says how you are treated for tax. So a customer who asks for your VAT number to apply the reverse charge cannot use your KvK number instead, and a validity check in VIES will only accept the VAT number.
Why the number matters
- Credibility: a registered number shows you are a real, traceable business.
- Verification: customers and suppliers can check who they are contracting with before they pay.
- Administration: banks, insurers and accounting software all use it as the key to your company record.
- Obligation: in the Netherlands the number belongs on your outgoing invoices.
The chamber of commerce number on your invoice
Dutch invoice requirements ask for both your KvK number and your VAT number, alongside the usual details: invoice number, date, the parties, the amounts per VAT rate and the total. Leaving one out is a formal defect, and it gives a customer a reason to hold payment while they ask for a corrected invoice. Read more about what belongs on an invoice.
Four common mistakes
- Giving the KvK number when the VAT number is meant. The most frequent mix-up, and it stalls cross-border invoicing, because the reverse charge needs a valid VAT number.
- Assuming a foreign number works the same way. Registers differ per country in name, length and what they record. A German HRB number and a Dutch KvK number are not equivalents you can swap.
- Thinking the number changes. It stays the same through a move, a rename or a change of activity. If you have two numbers, you probably have two registrations.
- Leaving it off invoices. It is a formal requirement in the Netherlands, and its absence is exactly the kind of detail that turns up in an audit rather than at the time.
Supplier numbers and invoice processing
When invoices are processed automatically, the registration numbers on the document do real work: they are how software recognises which supplier an invoice belongs to, even when the trade name on the letterhead differs from the registered name. TriFact365 reads these details off your purchase invoices and prepares a booking proposal in your own portal, which goes to your accounting package after your check. A supplier who states the number consistently is a supplier whose invoices need no manual sorting. Read more about automated invoice processing.
Frequently asked questions
It is the unique registration number your business receives when it is entered in the national business register. In the Netherlands it is the KvK number, issued by the Kamer van Koophandel and consisting of eight digits.
The KvK number is the Dutch chamber of commerce number: eight digits that identify your business in the public register. In English-language documents it also appears as CoC number or CCI number.
No. The KvK number identifies your business in the register; the VAT number is used for tax purposes and has the format NL, nine digits, B and two digits. A VIES check only accepts the VAT number.
On your registration extract, in the public register searchable by company name, on your own invoices and letterhead, and in your accounting software under your company details.
Eight. The RSIN, used for legal entities such as a BV or foundation, has nine digits, which is a useful way to tell the two apart at a glance.
No. It stays the same when you move premises, change your trade name or change activities. A new number means a new registration.
In the Netherlands, yes: invoice requirements ask for both the KvK number and the VAT number. Leaving one out is a formal defect and gives a customer grounds to request a corrected invoice.
In closing
Your chamber of commerce number is a small thing that carries a lot: it is how the outside world confirms your business exists and stays the same identifier for as long as it does. Keep it on your invoices, keep it apart from your VAT number, and the rest of your administration has one less thing to go wrong.
