Dutch invoice requirements for freelancers (2026 guide)

Dutch freelancers receive two VAT numbers from the Belastingdienst. Only one of them belongs on your invoices. The other contains your personal citizen service number (BSN), and putting it on a client-facing document is a genuine identity fraud risk. Most guides do not mention this. This one does. Below: the mandatory invoice fields, the BTW-ID vs. OB-nummer distinction, the KOR small-business exemption, and how to handle BTW for international clients.

The Dutch invoicing landscape: what makes it different

The Netherlands follows EU VAT rules but layers Dutch-specific requirements on top, including a mandatory KVK number and the dual VAT number system unique to sole traders.

The Netherlands follows EU VAT rules but layers Dutch-specific requirements on top, including a mandatory KVK number and the dual VAT number system unique to sole traders.

Dutch VAT is called BTW (Belasting Toegevoegde Waarde). The tax authority is the Belastingdienst. Dutch freelancers and self-employed professionals are called ZZP'ers (zelfstandige zonder personeel, literally "self-employed without employees"), and there are over 1.78 million of them as of 2025.

One key point: Dutch invoicing rules apply to you even if you are not based in the Netherlands. If you are billing a Dutch client, your invoice still needs to meet Dutch expectations, including correct BTW handling based on your status and location.

Now, the most important thing to get right, and the one most freelancers get wrong.

The dual VAT number trap: BTW-ID vs. OB-nummer

Dutch sole traders receive two VAT numbers from the Belastingdienst, and only the BTW-ID belongs on invoices; the OB-nummer is derived from your personal BSN and must never appear on client-facing documents.

Dutch sole traders receive two VAT numbers from the Belastingdienst, and only the BTW-ID belongs on invoices; the OB-nummer is derived from your personal BSN and must never appear on client-facing documents.

When a Dutch sole trader (eenmanszaak) registers with the Belastingdienst, they receive:

• BTW-identificatienummer (BTW-ID): format NL + 9 digits + B + 2 check digits, for example NL123456789B01. Designed for public use on invoices, quotes, and your business website. Contains no personal identity information. This is the number that goes on your invoices, always.
• Omzetbelastingnummer (OB-nummer): used exclusively for communications with the Belastingdienst, including VAT returns and tax correspondence. For sole traders, this number is derived from their personal BSN (Burgerservicenummer, citizen service number). Putting it on a client-facing invoice exposes your personal identity to fraud risk. It must never appear on any document a third party will see.

Why does this matter? The two numbers look similar and arrive in the same registration paperwork. Many freelancers, especially those new to the Dutch system, accidentally use the OB-nummer on invoices without realising what it contains.

The fix is simple: check your registration letter from the Belastingdienst. The BTW-ID starts with "NL" and ends with "B" followed by two digits. If the number you have been putting on invoices does not match that format, stop and switch to the correct one immediately.

Note: this dual number system only affects sole traders (eenmanszaak). If you operate through a BV (private limited company), you have a single VAT number that serves both purposes.

Invoicemonk uses your BTW-ID field for all client-facing documents. Your OB-nummer is never included.

The mandatory fields for a Dutch invoice

A compliant Dutch invoice must contain a specific set of fields, including the KVK number and BTW-ID that go beyond the EU baseline.

A compliant Dutch invoice must contain a specific set of fields, including the KVK number and BTW-ID that go beyond the EU baseline.

• Your business name and address: if you trade under a name different from your legal name, your trade name is fine, but your KVK registration must match.
• Your KVK number (Kamer van Koophandel): your 8-digit registration number from the Dutch Chamber of Commerce. Every invoice from a Dutch-registered business must include it.
• Your BTW-identificatienummer (BTW-ID): the NL + 9 digits + B + 2 digits format. Not your OB-nummer.
• Your client's full name and address.
• Your client's BTW number: required for cross-border EU B2B invoices where reverse charge applies. Always verify it on the EU VIES database before applying reverse charge.
• A unique sequential invoice number: an unbroken sequence with no gaps. If you void an invoice, document it; never reuse or skip the number. "2026-001, 2026-002..." is a clean, auditable format.
• Invoice date (factuurdatum).
• Date of supply (leveringsdatum): the date the service was delivered or the goods were transferred. Similar in spirit to Germany's Leistungsdatum.
• A clear description of services or goods: specific enough that a tax auditor understands what was delivered without asking.
• The taxable amount per BTW rate: the net amount before BTW is added.
• The BTW rate applied: the standard rate is 21%. The reduced rate of 9% applies to certain categories (food, books, some medical services). Most freelance services fall under 21%.
• The total BTW amount.
• The total gross amount payable.
• Payment terms: not legally required for VAT purposes, but Dutch business practice expects a specific due date. "Payment due by 15 June 2026" is better than "Net 30." The standard is 30 days.

One more Dutch-specific rule: you must send your invoice no later than the 15th day of the month following the month the service was delivered. Complete a project in May, the invoice goes out by 15 June.

Invoicemonk includes the KVK number and BTW-ID fields as standard. Sequential numbering is enforced automatically; gaps are not possible.

Do you need to charge BTW? The KOR exemption explained

Dutch freelancers with annual turnover of €20,000 or less can opt into the KOR (Kleineondernemersregeling) and stop charging BTW entirely, but the rules around invoice wording and the 3-year lock-in are strict.

Dutch freelancers with annual turnover of €20,000 or less can opt into the KOR (Kleineondernemersregeling) and stop charging BTW entirely, but the rules around invoice wording and the 3-year lock-in are strict.

The KOR threshold: annual turnover of €20,000 or less in the Netherlands.

What changes when you are on KOR:

• No BTW line appears on your invoices at all.
• Do not write "0% BTW"; that implies a different exemption (zero-rated supply) and will confuse your client's accountant.
• Instead, include this exact note: "BTW vrijgesteld op grond van artikel 25 Wet op de omzetbelasting 1968".
• Your invoice total equals the net amount; there is no gross/net distinction.
• You still need every other mandatory field: KVK number, BTW-ID, sequential numbering, and the rest.
• You cannot reclaim BTW on your own business expenses.

How to apply: submit the "Melding omzetbelasting kleineondernemersregeling" form via Mijn Belastingdienst Zakelijk at least 4 weeks before the start of the next quarter. Wait for written confirmation before treating any sales as BTW-exempt.

The 3-year commitment: once on KOR, you are locked in for a minimum of 3 years before you can voluntarily opt out. Plan accordingly.

New from 2025, the EU-KOR: Dutch freelancers can now apply for VAT exemption in other EU countries through the EU-KOR scheme, provided their total EU-wide turnover does not exceed €100,000 per year. This is a separate application from the domestic KOR and is optional; you can choose which EU countries it applies in.

For non-Dutch freelancers billing Dutch clients: KOR is only available to businesses established in the Netherlands. If you are based in Bulgaria, Nigeria, or the UK, KOR does not apply to you. Your own country's rules govern your VAT status, and for cross-border EU B2B services reverse charge typically applies regardless.

Cross-border invoicing: how BTW works for international clients

BTW treatment for cross-border work depends on whether your client is in another EU country, outside the EU, or whether you (the freelancer) are the one based abroad billing a Dutch client.

BTW treatment for cross-border work depends on whether your client is in another EU country, outside the EU, or whether you (the freelancer) are the one based abroad billing a Dutch client.

Here is where it gets interesting. Three scenarios cover almost every situation.

Scenario A: you are a Dutch ZZP'er billing an EU business client in another country. The reverse charge mechanism applies. You do not charge Dutch BTW. Instead, include your BTW-ID and your client's VAT number on the invoice and add the notation "BTW verlegd" (VAT reverse-charged). Your client accounts for the VAT in their own country. Always verify your client's VAT number via the EU VIES system before applying reverse charge. If the number turns out to be invalid, you are required to charge Dutch BTW at the standard rate, even if you already sent the invoice without it.

Scenario B: you are a Dutch ZZP'er billing a non-EU client (US, UK, Nigeria, etc.). No BTW applies. Include a note on the invoice explaining the exemption; the service is considered to be supplied outside the EU.

Scenario C: you are a non-Dutch freelancer billing a Dutch business client. Reverse charge applies. You do not charge your domestic VAT. Include the reverse charge notation on the invoice (in English, "VAT: reverse charge", or cite Article 196 of the EU VAT Directive). Include both your VAT number and your client's Dutch BTW-ID.

For a full explanation of how reverse charge works across all 27 EU member states, see our guide to EU VAT invoice requirements for freelancers. If your next client is in Germany, see our guide to invoicing German clients as a freelancer for the country-specific rules.

The most common Dutch invoice mistakes

Five mistakes account for almost every rejected Dutch invoice; each one is easy to prevent once you know to check for it.

Five mistakes account for almost every rejected Dutch invoice; each one is easy to prevent once you know to check for it.

• Using the OB-nummer instead of the BTW-ID: the OB-nummer is for Belastingdienst communications only. It contains your personal BSN and must never appear on client-facing invoices. Confirm your BTW-ID follows the NL + 9 digits + B + 2 digits format.
• Missing the KVK number: a Dutch-specific requirement that the EU VAT baseline does not include. Without it, the invoice is technically invalid under Dutch law.
• Writing "0% BTW" when on the KOR scheme: "0% BTW" implies a zero-rated supply, a different legal concept. KOR invoices must include the article 25 exemption wording instead.
• Not verifying the client's BTW number before applying reverse charge: if the client's VAT number is invalid, you remain liable for the BTW. Check every new client on VIES before sending the first invoice. For mistakes that need to be corrected after the fact, see our guide on how to issue a credit note.
• Missing or vague payment due date: "Net 30" is unclear. Dutch clients and their accountants expect a specific date. Use "Payment due by [exact date]" on every invoice.

Your Dutch invoice checklist

Bookmark or screenshot this checklist; it covers every field a Dutch client's accountant and the Belastingdienst will look for.

Bookmark or screenshot this checklist; it covers every field a Dutch client's accountant and the Belastingdienst will look for.

• Business name and address
• KVK number (8 digits)
• BTW-ID (NL format, not your OB-nummer)
• Client's name and address
• Client's BTW number (for cross-border EU invoices)
• Sequential invoice number with no gaps
• Invoice date and delivery date
• Specific description of services
• Net amount, BTW rate, BTW amount, gross total (or KOR exemption note)
• "BTW verlegd" notation for EU cross-border B2B invoices
• Specific payment due date

Invoicemonk handles all of this, including the BTW-ID field, sequential numbering, and reverse charge notation. Create your first Dutch-compliant invoice.

Invoicing across Europe? Start with our full guide to EU VAT invoice requirements for freelancers.

Frequently asked questions

What must a freelance invoice to a Dutch client include?

A Dutch invoice must include the freelancer's business name and address, their 8-digit KVK number (Chamber of Commerce registration), their BTW-identificatienummer (in NL + 9 digits + B + 2 digits format), the client's name and address, the client's BTW number for cross-border invoices, a unique sequential invoice…

A Dutch invoice must include the freelancer's business name and address, their 8-digit KVK number (Chamber of Commerce registration), their BTW-identificatienummer (in NL + 9 digits + B + 2 digits format), the client's name and address, the client's BTW number for cross-border invoices, a unique sequential invoice number, the invoice date, the date of supply, a clear description of services, the applicable BTW rate (21% standard or 9% reduced), the BTW amount, and the total gross amount. The invoice must be sent no later than the 15th day of the month following the month of supply.

What is the difference between a BTW-ID and an OB-nummer in the Netherlands?

the difference between a BTW-ID and an OB-nummer in the Netherlands is dutch sole traders (eenmanszaak) receive two VAT-related numbers.

Dutch sole traders (eenmanszaak) receive two VAT-related numbers. The BTW-identificatienummer (BTW-ID) is the public-facing number in the format NL + 9 digits + B + 2 digits; this is the number that belongs on invoices and client-facing documents. The omzetbelastingnummer (OB-nummer) is used only for communications with the Belastingdienst. For sole traders, the OB-nummer is derived from their personal BSN (citizen service number), which means putting it on a client-facing invoice creates an identity fraud risk. Only the BTW-ID should ever appear on invoices.

What is the KOR scheme and how does it affect Dutch freelance invoices?

The KOR (Kleineondernemersregeling) is a Dutch VAT exemption available to freelancers and small businesses with annual turnover of €20,000 or less.

The KOR (Kleineondernemersregeling) is a Dutch VAT exemption available to freelancers and small businesses with annual turnover of €20,000 or less. If you qualify and opt in, you stop charging BTW entirely. KOR invoices must not include a BTW line or write "0% BTW"; instead, they must include the note "BTW vrijgesteld op grond van artikel 25 Wet op de omzetbelasting 1968." All other mandatory fields (KVK number, BTW-ID, sequential numbering) still apply. KOR participants cannot reclaim BTW on their business expenses and must commit to the scheme for at least 3 years before opting out.

What does "BTW verlegd" mean on a Dutch invoice?

"BTW verlegd" is the Dutch phrase for "VAT reverse-charged.

"BTW verlegd" is the Dutch phrase for "VAT reverse-charged." It appears on invoices when a Dutch freelancer bills a VAT-registered business in another EU country. Under the reverse charge mechanism, the Dutch freelancer does not charge BTW; instead, the client accounts for the VAT in their own country. The invoice must include both the freelancer's BTW-ID and the client's VAT number, and the words "BTW verlegd" must appear on the invoice. The client's VAT number should always be verified on the EU's VIES database before applying reverse charge treatment.

Does a non-Dutch freelancer need to include a KVK number when invoicing a Dutch client?

No.

No. The KVK number (Dutch Chamber of Commerce registration number) is only required on invoices from businesses registered in the Netherlands. A freelancer based outside the Netherlands does not have a KVK number and is not required to include one. The invoice must still comply with EU VAT rules, include the correct reverse charge notation and both VAT numbers for B2B cross-border invoices, and meet the Dutch client's own invoicing expectations.