VAT Number Display: NL Sole Proprietors, Watch Out for BSN

If you're a Dutch sole proprietor and your old BTW-nummer is still on your website, you're publishing your BSN for the entire internet to see. That's a real identity fraud risk, and it's easy to fix.

Here's what happened, why it matters and what to do about it.

The BSN problem

Before 2020, the Belastingdienst gave every eenmanszaak a BTW-nummer that was based directly on the owner's BSN (burgerservicenummer). The format looked like this:

NL + [your 9-digit BSN] + B + 2 digits

Your BSN is basically your Dutch social security number. It's used for taxes, healthcare, pensions and government services. It was never meant to be public information.

But if you ran a business, the tax office built your VAT number around it. And then the law said you had to display that number on your website and invoices. So millions of self-employed people had their BSN sitting in plain text on their business pages.

What changed in 2020

The Belastingdienst recognized the problem and rolled out a new number in January 2020: the BTW-identificatienummer (BTW-ID).

The format looks similar:

NL + 9 random digits + B + 2 digits

The difference is that those 9 digits are random. They have no connection to your BSN. Every sole proprietor received a letter with their new BTW-ID, and the Belastingdienst asked everyone to switch.

Your old BTW-nummer still exists for tax filings and communication with the Belastingdienst. But it should never appear on your website, your invoices or anywhere the public can see it.

Why this matters

Having your BSN on your website opens the door to identity fraud. Someone with your BSN, name and address can:

• Open bank accounts or credit cards in your name
• File fraudulent tax returns
• Apply for benefits or loans
• Access government services pretending to be you

The Autoriteit Persoonsgegevens (Dutch data protection authority) has been clear: displaying your BSN publicly is a privacy violation. You're not just risking your own data. Under the GDPR, you could face complaints from clients who argue you should have known better.

How to find your BTW-ID

Two options:

1. Log in to Mijn Belastingdienst. Your BTW-ID is listed under your business details. Look for "BTW-identificatienummer."
2. Check the letter from 2020. When the new system launched, the Belastingdienst sent every sole proprietor a letter with their new BTW-ID. If you kept it, the number is right there.

If you can't find either, call the BelastingTelefoon at 0800-0543. They can look it up for you.

Where to display your BTW-ID

Dutch law and the EU VAT Directive require your VAT identification number on:

• Your website footer (visible on every page)
• Your contact page or impressum
• Your terms and conditions
• Every invoice you send

A clean footer example:

"De Digitale Bakker | KVK 12345678 | BTW-ID NL123456789B01 | Amsterdam"

Make sure it's the BTW-ID, not the old BTW-nummer. The easiest way to tell: if the 9 digits match your BSN, it's the wrong one.

What about BVs and other legal entities?

Good news if you run a BV, VOF or other legal entity. Your VAT number was never based on anyone's BSN. The identity fraud risk doesn't apply to you in the same way.

That said, double-check that the number on your website is correct and current. Companies sometimes display an old or incorrect VAT number after restructuring. You can verify your number at the Belastingdienst portal or through the EU VIES system.

Quick fix checklist

1. Log in to Mijn Belastingdienst and copy your BTW-ID
2. Search your website for any instance of your old BTW-nummer (check footer, contact page, terms, privacy policy)
3. Replace every occurrence with your BTW-ID
4. Check your invoice templates too
5. Do a quick search on Google: site:yourwebsite.nl plus your BSN digits, to make sure nothing slipped through

Total time: 15 minutes. The peace of mind is worth it.

Not sure if your website has other compliance gaps? Run a free scan and we'll check your legal information, cookies, accessibility and more.

Related guides

• KVK Number on Your Website: Is It Required?
• Impressum Requirements Across Europe
• Webshop Compliance in the Netherlands

Frequently asked questions

Can I still use my old BTW-nummer for tax filings?

Yes. The old BTW-nummer is still valid for communication with the Belastingdienst, like filing your BTW returns. You just can't use it in public. On your website, invoices and anything client-facing, always use the BTW-ID.

How do I know which number is which?

Compare the first 9 digits (after "NL") to your BSN. If they match, it's the old BTW-nummer and you need to replace it. If they don't match, you're already using the BTW-ID. You can also check Mijn Belastingdienst where both numbers are listed separately.

What if I never received a BTW-ID?

Every active sole proprietorship should have received one in 2020. If you started your business after January 2020, you would have received a BTW-ID from the start. If you somehow never got one, call the BelastingTelefoon at 0800-0543 to request it.

Does this apply to businesses outside the Netherlands?

The BSN issue is specifically Dutch. But the requirement to display a VAT number on your website applies across the EU. Each country has its own format. If you sell to customers in other EU countries, you need to display your VAT identification number regardless of where you're based.