Checking a VAT number for a new customer: VIES or KBO/BCE, and what to look at

Why you check a VAT number before the first invoice

Checking a VAT number takes a minute, if you know where to look. A wrong number costs more: an invoice that comes back, a credit note and a new invoice, and a payment that waits until everything is right. It usually goes wrong in one of these places:

• The number was given over the phone. Two digits are swapped, or one is missing.
• It is the number of another company in the group. The manager of a building calls, but the invoice must go to the company that owns it.
• The company is no longer what the customer says. It has ceased trading, been taken over or changed its name.
• The name on the order is a trading name. The official name and the address of the registered office are different, and the boiler is often at a third address.

If an incorrect invoice has gone out anyway, read how to issue a credit note.

What does a Belgian VAT number look like?

Every company in Belgium has a ten-digit company number, which it receives when it registers with the Crossroads Bank for Enterprises (KBO/BCE). The VAT number is the same number, with BE in front of it. It must be activated with the FPS Finance (FOD Financiën / SPF Finances) if the company carries out activities subject to VAT (business.belgium.be, in French). So a company number is not always an active VAT number.

• BE and ten digits. Full stops and spaces are only a way of writing it: BE0123.456.789 and BE 0123 456 789 are the same number.
• The first digit is 0 or 1. The series starting with 0 had run out. Since 19 September 2023, new companies receive a number starting with 1, and existing companies keep their number (FPS Economy, in French).

Checking a VAT number: VIES or KBO/BCE?

For a Belgian customer you look in the KBO/BCE, for a customer in another EU country in VIES. The two answer a different question.

In the KBO/BCE, you search KBO Public Search (in French) by number, name or address. It shows every registered company, including those that have ceased trading: so look at the status. If the company is subject to VAT, the section on its capacities (“Hoedanigheden” / “Qualités”) shows the entry “subject to VAT” (“Onderworpen aan btw” / “Assujettie à la TVA”), with the date from which it applies (efacture.belgium.be, in French).

In VIES, you choose the country and enter the number. VIES searches that country’s VAT database and says whether the number is valid (Your Europe, in French).

What do you do if VIES shows “not valid”?

“Not valid” means that VIES did not find the number in the national VAT database. According to the European Commission, there can be three reasons: the number does not exist, it has not been activated for trade between EU countries, or the registration has not yet been completed.

1. Check what you entered. The right country code, the right number of digits, no letter O instead of a zero.
2. Look up a Belgian customer in the KBO/BCE. Is the company active and subject to VAT?
3. Ask for the number from a document. An invoice or the customer’s letterhead is more reliable than the memory of the person calling.
4. Let the customer sort it out. If the number stays not valid, the customer can have it checked by their tax authority. In that case the Commission refers to the national authorities.
5. Keep your check. The Commission recommends keeping the result of your check, in case of a tax audit. Note the date and keep it with the customer file.
6. Do not invoice on a hunch. Put the case to your accountant before you make the invoice. They know what it means for the VAT on that invoice.

Must the customer’s VAT number be on the invoice?

Your own VAT number is on all your invoices (Your Europe, in French). For the customer’s number, the European VAT rules say that a full VAT invoice states it when the customer is liable for the VAT on that transaction themselves, as with the reverse charge (European Commission). Belgium may require additional items of its own on top of that. Have your accountant check once which items your invoices must contain.

Whether a customer is subject to VAT also determines how your invoice goes out. Since 1 January 2026, Belgian companies subject to VAT send each other structured electronic invoices via the Peppol network. That obligation does not apply to invoices to private customers (efacture.belgium.be, in French). What the obligation involves is explained in e-invoicing via Peppol, and how an intervention becomes an invoice in from work order to invoice.

A private customer does not give you a VAT number. If a self-employed person orders for their home, ask whether it is for their business and have your accountant take a look.

Checklist: creating a new business customer

1. Ask for the official name, the VAT number, the registered office address, a separate billing address if there is one, the email address for invoices, and whether the customer is ordering as a company or as a private individual.
2. Look up a Belgian company in the KBO/BCE: status, subject to VAT, name and registered office address.
3. Check the number of a customer in another EU country in VIES, and keep the result.
4. Copy the name and address as they appear in the register, and always write the VAT number in the same format.
5. Note the address of the work separately: the location of the installation is not always the registered office.
6. Check whether the customer already exists before you create a new record.
7. If a customer reports a new name, a takeover or a different billing address, check again.

An example: a new customer for boiler maintenance

A heating company gets a call from a property manager: can it maintain the boiler room of an office building? The manager gives a name and a VAT number. The office employee looks it up in the KBO/BCE: the number belongs to the property management firm itself.

She calls back and asks who pays the invoice: the company that owns the building. The manager sends an old invoice with that company’s number. In the KBO/BCE, that company is active and subject to VAT, with its registered office in another municipality. The employee creates the customer with the official name and the registered office address, adds the office building as the site of the work and adds the manager as a contact person. The first invoice goes to the right company.

How it works in Digitalnatie Service Suite

Creating a customer

• In the customer list, you create a new customer. The name, street and number, postcode and municipality are required. You add the VAT number if you have it, in the format BE0123.456.789.
• A box that is ticked by default creates a site at that address at the same time. If the work takes place elsewhere, untick it and add the right site from the customer file.
• If the VAT number or the name already exists, Service Suite refuses to create the customer, and the message names the existing customer, which you can open. In the customer list, you can also search by VAT number.

Retrieving the official data (VIES / KBO/BCE)

• In the customer file, you open the editing of the customer data. Once the VAT number has been saved, a lookup retrieves the company’s official data.
• You tick what you want to take over, then confirm. A field that is already filled in is only replaced if you tick it.
• A separate billing address is added as a contact of the billing type, with its own address.
• In the default roles, the administrator, the manager, the planner, accounting and sales can create and edit customers.

Your own data and Peppol

• In the company profile, the administrator enters your company’s VAT number, company number (KBO/BCE) and the bank account (IBAN) printed on invoices. The VAT number is checked when it is saved.
• Your company is registered on Peppol at the start, together with Digitalnatie (KBO number, agreement, verification). If your organisation is connected to Peppol, sending a posted invoice offers Peppol when the customer is on Peppol. Otherwise that option is greyed out, with the reason.

Good to know: the lookup of the official data works on a VAT number that has already been saved, not in the window for creating a customer. So you create the customer first, then run the lookup. Merging two customers is not possible in the application, so it is best to avoid a duplicate record from the start. To keep a record of a VIES check, upload the printout as a PDF to the files of the customer file (10 MB at most).

A complete customer list is imported by the administrator from the configuration, with a check that also counts duplicates: see importing customer data. What else you keep for a customer is in the customer file.

Frequently asked questions

How do I check a VAT number?

You look up a Belgian VAT number in KBO Public Search of the FPS Economy: it shows whether the company is active and subject to VAT, with its official name and registered office address. You check a VAT number from another EU country in VIES, the European Commission’s search engine. Keep the result of your check.

What is the difference between VIES and the KBO/BCE?

The KBO/BCE is the register of Belgian companies: it shows a company’s official data and whether it is subject to VAT. VIES searches the VAT databases of the EU countries and says whether a VAT number is valid for trade between EU countries. For a Belgian customer you start with the KBO/BCE, for a customer in another EU country with VIES.

How many digits does a Belgian VAT number have?

Ten digits, preceded by BE. The VAT number is the company number with BE in front of it. The first digit is 0 or 1: since 19 September 2023, new companies receive a number starting with 1.

Must the customer’s VAT number be on the invoice?

Ask every business customer for it in any case: you need it to check them. According to the European VAT rules, it appears on a full VAT invoice when the customer is liable for the VAT on that transaction themselves, as with the reverse charge. Belgium may require additional items of its own: have your accountant check which items your invoices must contain.

Can Service Suite look up a VAT number when you create a customer?

No, not in the window for creating a customer. You create the customer with their VAT number and then, in the customer file, open the editing of the customer data, where a lookup retrieves the official data. You choose yourself which data you take over.