BTW-id vs KvK Number vs BSN: Dutch Business Numbers Explained for Freelancers (2026)

Start freelancing in the Netherlands and within weeks you're juggling four different numbers: a BSN, a KvK number, a btw-id and an omzetbelastingnummer. They all look vaguely similar, clients keep asking for "your tax number," and one of them you must never share. This guide — part of our series on freelancing in the Netherlands without speaking Dutch — explains what each number is, who issues it, what it looks like, and exactly where it must (and must never) appear.

All Dutch Numbers at a Glance

This is the cheat sheet. All example numbers below are fake — they only show the format.

BSN: Your Personal Number (Not a Business Number)

The burgerservicenummer (BSN) is a 9-digit personal number that identifies you to Dutch government agencies — for tax filing, healthcare, allowances and payroll records. It is strictly personal, not a business identifier, even though your business "borrows" it behind the scenes (a sole trader's OB-nummer is built on it).

How you get one depends on how long you stay. Staying 4 months or more? Register with your gemeente (municipality) in the BRP, the Personal Records Database — your BSN is issued automatically at registration. Staying under 4 months or living abroad? Register in person at one of the 19 RNI desks (Registratie Niet-Ingezetenen) — including Amsterdam, Rotterdam, The Hague, Utrecht, Eindhoven and Groningen — and you receive your BSN immediately, free of charge. Note: non-EU/EEA nationals can only book at the Breda or Venlo desks.

KvK Number: Proof You Are a Registered Business

The KvK number is your 8-digit registration number in the Handelsregister (Business Register), issued by the Kamer van Koophandel (Chamber of Commerce). It tells clients, suppliers and banks that you are a bona-fide registered business. You get it on the spot at your KvK registration appointment, after paying the one-off fee of €85.15 (2026). Our step-by-step guide to KvK registration for foreign freelancers walks you through the whole appointment.

Where must it appear? Almost everywhere. Dutch law (Handelsregisterwet 2007) requires your KvK number on letters, quotations, invoices, your website and business emails. Omitting it is classified as an economic offence, so treat this as a hard rule, not a formality. There is no downside to sharing it — the KvK number is public by design.

Btw-id: Your Public VAT Identification Number

The btw-id (btw-identificatienummer) is what most people mean by "Dutch VAT number." For a sole trader it looks like NL123456789B01 (fake example): NL + 9 digits + B + a 2-digit sub-number — 14 characters in total. Crucially, since 1 January 2020 those 9 digits are random: they are not your BSN, so the number is safe to publish anywhere.

You don't apply for it separately: KvK notifies the Belastingdienst when you register, and if you qualify as a VAT entrepreneur your btw-id (together with your OB-nummer) arrives by post within roughly 2 weeks / 10 working days. It must appear on your invoices, quotations, letterhead and website — and for EU B2B transactions you must also state your customer's VAT identification number. You can verify any EU VAT number for free with the European Commission's VIES tool, and even save a Consultation Number as official proof that you checked.

OB-nummer: The VAT Number Only the Tax Office Sees

Here is where most internationals get tripped up: alongside the btw-id you also receive an omzetbelastingnummer (OB-nummer) — and for a sole trader it is a different number. It consists of 9 digits + B + 2 digits, and those 9 digits are your BSN (fake example: 111234567B01). You use the OB-nummer exclusively in communication with the Belastingdienst: filing your VAT return, letters, calling the tax phone line. That's it. Because it contains your BSN, it must never appear on invoices, your website or anything else a third party sees. When you file your first Dutch VAT return, the OB-nummer is the one the portal is referring to.

The Numbers Most Freelancers Can Ignore

RSIN — for legal entities, not for you

The RSIN is a 9-digit number that links a legal entity's data across government registers — think of it as the business equivalent of the BSN. BVs, foundations, associations and partnerships (VOF, CV, maatschap) get one from KVK at registration. Sole traders do not get an RSIN: as a natural person, your BSN plays that role. If you run an eenmanszaak, you can cross this one off entirely.

Loonheffingennummer — only if you hire staff

The LH-nummer (payroll tax number) is an employer identifier from the Belastingdienst, needed to remit payroll taxes and file payroll tax returns. You only get one if you register as an employer — for instance by ticking "I plan to hire staff" during KvK registration. A solo freelancer with no employees never needs one.

DigiD vs eHerkenning — your login, not a number

One nuance: if you own a BV or partnership next to your sole proprietorship, you do need eHerkenning for those entities — DigiD only covers you as a natural person. And the government's eHerkenning compensation scheme does not apply to sole traders, precisely because they can use free DigiD.

In What Order Do You Get Them?

Four Common Mix-ups

The Invoice Number Check

Before an invoice leaves your outbox, run it through this 30-second check. For everything else an invoice legally needs (sequential numbering, dates, VAT breakdown), see our full guide to Dutch invoice requirements.

Frequently Asked Questions

Conclusion

Once you see the pattern — personal vs business, public vs private — the Dutch number soup becomes surprisingly logical. Bookmark the table at the top, and the next time a client asks for "your tax number," you'll know exactly which one to send.