Short answer
In the Netherlands, a business registered with the Chamber of Commerce (KVK) must show its 8-digit KVK number on every invoice, together with its VAT ID (btw-id), not its VAT tax number. In Belgium, every registered enterprise must show its 10-digit enterprise number (ondernemingsnummer) on invoices; the Belgian VAT number is BE followed by the same digits.
This guide is for freelancers and small-business owners in the Netherlands or Belgium, including expats. It explains when the KVK number on invoices is required, how the Belgian enterprise number works, which customer details to include and how these numbers become Peppol IDs.
In the Netherlands: is a KVK number required on invoices?
Yes, if your business is in the Dutch Business Register (Handelsregister). Article 27 of the Trade Register Act 2007 (Handelsregisterwet) requires registered businesses and legal entities to show their registration number on letters, orders, invoices, quotes and other notices, advertising excepted. The Belastingdienst (Dutch Tax Administration) lists it among its invoice requirements too.
The KVK number has 8 digits; a business has only one, even with several trade names. The 12-digit branch number (vestigingsnummer) is not required. KVK also wants the number on your website and in business emails.
A bv or nv must also clearly show its full name and registered office (statutaire zetel), under the Dutch Civil Code. Omitting the KVK number is an economic offense under the Economic Offences Act.
Dutch VAT ID or VAT tax number: which goes on the invoice?
Use your VAT identification number (btw-id), which starts with NL, such as NL123456789B01. Your VAT tax number (omzetbelastingnummer) is only for dealing with the Belastingdienst; for sole proprietors it contains the citizen service number (BSN), so keep it off invoices.
If you use the small businesses scheme (kleineondernemersregeling, KOR) or your supplies are VAT-exempt, KVK says your btw-id does not have to be on the invoice. Your KVK number is still required.
| Number | Example | On the invoice? |
|---|---|---|
| KVK number | 12345678 (8 digits) | Yes, if registered with KVK |
| VAT ID (btw-id) | NL123456789B01 | Yes, unless you use the KOR or are VAT-exempt |
| VAT tax number (omzetbelastingnummer) | 111234567B01 | No, only for contact with the Belastingdienst |
| Branch number (vestigingsnummer) | 12 digits | Not required |
Can you invoice in the Netherlands without a KVK number?
Yes, if you do not have to register. Registration is required when you independently supply products or services, charge a price that earns money and regularly supply people other than family or friends. A hobby that earns little or nothing is not a business under the Trade Register Act.
Not registered with KVK but registered for VAT? Then you can send a normal invoice without a KVK number. If you do not have to register and your annual turnover is €2,200 or less, the registration threshold (registratiedrempel) applies: you charge no VAT and need not issue invoices for VAT purposes.
In Belgium: is the enterprise number required on invoices?
Yes. Every enterprise that must register with the Crossroads Bank for Enterprises (KBO) shows its enterprise number (ondernemingsnummer) on all deeds, invoices, letters, orders and other documents, under article III.25 of the Code of Economic Law. The same article also requires the number of at least one payment account the enterprise holds with a bank in the European Economic Area.
The enterprise number has 10 digits and starts with 0 or 1; numbers starting with 1 have been issued since September 19, 2023. The Belgian VAT number is BE followed by the same 10 digits, and VAT-registered businesses show it as well.
Legal entities such as a bv, nv or vzw also need their name, legal form, exact registered office address and "RPR" (legal entities register) followed by the court of the registered office, under article 2:20 of the Code of Companies and Associations. Where applicable, add the email address, website and the fact that the entity is in liquidation.
Example: company details on an invoice from a Belgian bv
[Name] bv Registered office: [street and number], [postcode] [municipality] Enterprise number: 0123.456.789 VAT: BE 0123.456.789 RPR Gent, afdeling Brugge IBAN: [account number] at [bank] Invoice 2026-0042, dated September 24, 2026 Date of service: September 22, 2026 Customer: [customer name] bv, [address], VAT BE 0987.654.321 Consulting: 10 hours × €80.00 = €800.00 VAT 21%: €168.00 Total due: €968.00
Which customer numbers belong on the invoice?
Netherlands: your customer’s full name and address are required; their KVK number is optional. Their VAT ID is required when VAT is reverse-charged (btw verlegd) and when you supply goods or services to a business in another EU country.
Belgium: a VAT invoice shows the customer’s name, address and, for a VAT-registered business customer, its VAT number (Royal Decree No. 1 on VAT, article 5). For a consumer, name and address are enough.
Before the first invoice, check KVK numbers in the KVK Business Register, Belgian enterprise numbers in KBO Public Search (its "Hoedanigheden" section shows VAT status) and EU VAT numbers in VIES.
KVK: search the Dutch Business Register (in Dutch)
How do company numbers become Peppol IDs?
Since January 1, 2026, Belgian VAT-registered businesses must exchange structured e-invoices with each other, using software that works through the Peppol network. The Belgian convention is to register at least the enterprise number, under scheme 0208 (for example 0208:0123456789, without dots); the VAT number (scheme 9925) or other identifiers can be added if trading partners agree.
Dutch businesses can use their KVK number as a Peppol ID under scheme 0106, such as 0106:12345678, or their VAT number under scheme 9944.
Belgian e-invoicing portal: what is a Peppol ID?
Company details on every invoice with Factuur Simpel
In Factuur Simpel you enter your company details once, and they appear on every invoice automatically, with your IBAN and, if saved, your customer’s KVK or VAT number. Extra statements, such as a Belgian RPR line or a Dutch bv’s registered name, go in a custom footer.
The Complete plan adds sending and receiving invoices through Peppol, registered with your KVK or VAT number in the Netherlands, or your enterprise or VAT number in Belgium.
Frequently asked questions
Is the KVK number the same as the Dutch VAT number?
No. KVK issues the 8-digit KVK number, which shows that your business is in the Business Register. The Belastingdienst issues the VAT ID (btw-id), such as NL123456789B01, which shows that you are registered for VAT. Invoices normally carry both; with the KOR or VAT-exempt supplies, the VAT ID can be left off.
Is the Belgian enterprise number the same as the VAT number?
They share the same 10 digits: the VAT number is BE plus the enterprise number. They are still separate requirements: every KBO-registered enterprise shows its enterprise number on invoices, and VAT-registered businesses also show the VAT number. KBO Public Search shows under "Hoedanigheden" whether a business is subject to VAT.
Do I need my customer’s KVK number on a Dutch invoice?
No, it is optional. The Dutch invoice requirements ask for your customer’s full name and address. Adding the KVK number can help identify the right company when names are similar. The customer’s VAT ID is required when VAT is reverse-charged and for supplies to businesses in other EU countries.
Does a Belgian sole trader need an RPR line on invoices?
No. The RPR line in article 2:20 of the Code of Companies and Associations applies to legal entities such as a bv, nv or vzw. A sole trader still shows the enterprise number, a payment account held by the business and, if VAT-registered, the VAT number, alongside their name and address.
Get your company details right on every invoice
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