Chamber of Commerce number of a new supplier: do you ever actually check it?

A Chamber of Commerce number appears in almost every email signature, but hardly anyone actually verifies it. A shame, because in two minutes you can confirm whether you're really dealing with who you think you are.

You open an email from a new supplier. Neat signature, logo looks right, everything appears professional. At the bottom is the Chamber of Commerce (CoC) number. But… do you ever actually check it? Most SMB owners don't. Which is a pity, because a CoC check takes literally thirty seconds and can sometimes turn up surprising information.

Why you should check the CoC number

A CoC number is public and free to look up. Yet we tend to treat it as a decorative element in an email signature — even though it can reveal things you'd want to know before signing a quote or making a down payment:

• Does the company actually exist?
• How long has it been registered? (A company from last week versus one that's been around for 20 years makes quite a difference.)
• Does the address match what's on the quote?
• Is the person sending the email authorised to sign?
• Has the company recently been deregistered or declared bankrupt?

This is especially relevant with new suppliers, subcontractors, or larger contracts. It's also worth doing when you reconnect with an old contact after several years — companies merge, change their legal form, or cease trading without you ever finding out.

What you can verify in two minutes

Go to kvk.nl/zoeken and enter the number or company name. Everything you see there is publicly visible. Run through this list:

1. Does the registration exist? It sounds obvious, but invoice fraud regularly involves made-up CoC numbers or numbers copied from a legitimate company.
2. Does the name match what's on the quote or invoice? "Jansen Bouw B.V." and "Jansen Bouw & Onderhoud B.V." are two different legal entities.
3. Does the registered address match? Compare it with the signature in the email. A company claiming to be based in Utrecht but registered in Romania — that's a red flag.
4. Who is authorised to sign? For a B.V., the register shows who has sole or joint signatory authority. If the contact in the email isn't listed, it's reasonable to ask a follow-up question before committing to a large amount.
5. Date of registration. A company that's three weeks old and immediately wants a €40,000 contract isn't automatically suspicious — but it is a reason to make an extra call.
6. Is there a bankruptcy or dissolution listed? That shows up immediately under the status.

When should you run this check?

You don't need to screen every supplier of pens and paper. But you should check:

• For a first order with a new party.
• Before making a down payment.
• Before signing a contract or framework agreement.
• When an existing supplier suddenly provides a different IBAN or account name.
• For a subcontractor brought in by your main contractor — you're indirectly dependent on them too.

Combine it with a VAT and IBAN check

A CoC number tells you about the registration, not about VAT liability or the bank account. For a complete picture, add two quick checks on top:

• Check the VAT number using our VAT check. This confirms whether the number is valid and whether the name matches.
• Check the IBAN with our IBAN check. Useful for spotting typos and confirming the format matches the country.

These three together — CoC, VAT, and IBAN — form a small but solid barrier against the most common forms of invoice and supplier fraud. And you can get it done in two to three minutes per new supplier.

Build it into your process

The pitfall with these kinds of checks is that one person does them and everyone else doesn't. So make it a small but fixed part of your standard purchasing workflow. For example:

• Adding a new supplier in your accounting system? → Note the CoC number, VAT number, and IBAN alongside it, with the date and initials of whoever ran the check.
• Bank account change? → Run the same three checks again, and confirm by phone using a number you already had on file — not the number from the email.
• Large quote? → Save a screenshot of the CoC registration in the file.

This isn't bureaucracy — it's just one line on a checklist. But if something ever goes wrong and your insurer or accountant asks "did you verify the other party?", you'll have an answer.

What a CoC check is not

To be clear: a valid CoC registration is not a quality mark. Perfectly reputable companies are listed alongside fraudulent ones. What it gives you is basic information: does the company exist, does the address check out, who is authorised to sign. The rest — reviews, references, creditworthiness — is a separate matter.

Think of it as the lock on your office door. It won't stop a determined criminal, but it does filter out opportunistic attempts. And that's usually what invoice fraud is all about: opportunity.

Quick summary

• Checking a CoC number takes thirty seconds and is free.
• Do it for new suppliers, down payments, contracts, and IBAN changes.
• Combine with a VAT and IBAN check for the full picture.
• Record who checked it and when — that saves arguments later.

Want to check a party right now? Run the VAT check and IBAN check alongside your CoC lookup. Three screens open, two minutes of work, a lot of peace of mind.