The short answer
A Belgian enterprise number (ondernemingsnummer in Dutch, numéro d'entreprise in French) is the ten-digit identifier the Crossroads Bank for Enterprises (KBO/BCE) gives every registered company, association and self-employed person. It is written 0xxx.xxx.xxx, and since 19 September 2023 new numbers start with 1. The last two digits are check digits: 97 minus the remainder when the first eight digits are divided by 97. The VAT number is the same number with BE in front, but only if the company is subject to VAT. To find a company's number, search its name in KBO Public Search at kbopub.economie.fgov.be, which is free and needs no account. Legal entities must show the number on invoices, letters and their website.
The rules below come from the Royal Decree of 24 June 2003, the Code of Economic Law and the Code of Companies and Associations on Justel, the FPS Economy's technical manual for KBO data and KBO Public Search itself, read on 30 September 2026.
What the number looks like
The enterprise number has ten digits, written ZNNN.NNN.NNN. The royal decree that sets the format says the first digit is 0 or 1, that a leading 0 does not have to be shown, and that digits nine and ten form the check digit. So 0202.239.951 and 202.239.951 are the same number.
Numbers started with 0 from the launch of the KBO on 1 July 2003 until that series ran out. The FPS Economy announced on 22 September 2023 that the first number starting with 1 had been issued on 19 September 2023. Existing companies keep their 0 number. The number cannot be transferred to another enterprise, and a struck-off number is never reissued.
Identifier | Written as | First digit | Who has one |
|---|---|---|---|
Enterprise number | 0202.239.951 | 0 or 1 | Every registered entity: companies, associations, self-employed people |
Establishment unit number | Z.NNN.NNN.NNN | 2 to 8 | Every place of business of a registered entity |
VAT number | BE0202239951 | BE, then 0 or 1 | Only entities subject to VAT |
How to check an enterprise number with modulo 97
The FPS Economy's technical manual for reusing KBO data describes positions one to eight as a sequence number and positions nine and ten as the check digit, calculated as "97 - modulo 97". Take the first eight digits, divide them by 97 and subtract the remainder from 97. The result must equal the last two digits. A worked example with Proximus, whose enterprise number in KBO Public Search is 0202.239.951:
The first eight digits are 02022399, which is 2,022,399.
2,022,399 divided by 97 is 20,849 with a remainder of 46, because 97 times 20,849 is 2,022,353.
97 minus 46 is 51.
The last two digits are 51, so the number is well-formed.
If the remainder is 0, the check digits are 97. The manual applies the same rule to establishment unit numbers. In a spreadsheet, with the number as ten-digit text in cell A2 and no dots, =97-MOD(VALUE(LEFT(A2,8)),97)=VALUE(RIGHT(A2,2)) returns TRUE for a well-formed number; Dutch and French Excel use semicolons and translated function names.
What the check does not tell you is that the number exists. 1000.000.021 passes it, and KBO Public Search answers that this number does not exist. Only the register confirms the company.
Enterprise number and VAT number
The Belgian VAT number is the enterprise number with BE in front: BE0202239951, often printed as "BTW BE 0202.239.951" on Dutch-language invoices. The FPS Economy puts the condition plainly: if your activity is subject to VAT, you state the VAT number, which is BTW BE followed by the enterprise number. So every Belgian VAT number is an enterprise number, but an association or holding company without VAT activity has an enterprise number and no VAT registration.
In KBO Public Search, the Characteristics section shows "Subject to VAT" with a start date; for Proximus it reads 1 January 1971. For intra-EU invoicing, also validate the number in VIES, and read how to check an EU VAT number for what a valid result does and does not prove.
Establishment unit numbers
Each place of business of an enterprise is an establishment unit with its own ten-digit number, written Z.NNN.NNN.NNN, where the first digit is 2 to 8. Proximus has 186 of them. The number identifies a place, not a company, and unlike the enterprise number it moves with the establishment when that is transferred to another enterprise. If a Belgian number starting with 2 matches nothing in your CRM, that is usually why. Establishment units in the Belgian register explains what this does to prospect lists.
How to look up an enterprise number by name
Open KBO Public Search at kbopub.economie.fgov.be. It is free, needs no account and has an English interface.
Search by name. The search is phonetic, so spelling variants still match. Add the postal code for common names, and tick "Inclusive of old names" if the company may have been renamed.
Set the filter. "Only active registered entities and active establishment units of active entities" hides stopped companies; untick it to check a former customer.
Open the record. The enterprise number is at the top, followed by Status (active or stopped) and Legal situation (normal, or for example bankruptcy or liquidation). Read both.
Check the date. Each record states the situation of the database on a given day. On 30 September 2026, the Proximus record showed data as of 29 September.
For a full walkthrough of a record, see the Belgian company register guide, and for which free source answers which question, where to find Belgian company data. Public Search is built for lookups by hand; the FPS Economy prohibits reusing data from the website, and the routes for volume are compared in every way to get KBO data into your software.
Where a company must show its number
Code of Companies and Associations, article 2:20. All deeds, invoices, announcements, publications, letters, orders, websites and other documents of a legal entity, electronic or not, must state its name, legal form, the exact address of its registered office, its enterprise number, "RPR" (in French "RPM") followed by the court of the registered office, its email address and website where it has them, and whether it is in liquidation.
Code of Economic Law, article III.25. Every enterprise that must register in the KBO, sole traders included, must show its enterprise number on all deeds, invoices, announcements, letters, orders and other documents, with at least one payment account it holds at a credit institution in the European Economic Area.
Code of Economic Law, article XII.6. A business providing services online must give easy, direct and permanent access to its enterprise number where it has one, and to its VAT number if it is subject to VAT.
Under article 2:22, someone who takes part in a deed or website on behalf of a legal entity that breaks these rules can, depending on the circumstances, be held liable for the entity's commitments. In practice, check the invoice, the email footer or the website's legal notice before you search. This is general information, not legal advice.
Using the number as the key in your CRM
A number that is unique, permanent and printed on every invoice is the field to match Belgian companies on. Store it as ten-digit text so the leading zero survives, accept numbers starting with 1 (validation rules written before 2023 may reject them), and run the modulo 97 check at entry before confirming the company in the register.
Bizzy works the same way. It carries the enterprise number on every Belgian company record and keys its integrations for HubSpot, Teamleader Focus and Odoo on it: a company you push arrives with its number, and an existing record is completed field by field under rules you set, not matched on a name. How the HubSpot integration matches and completes records shows the settings, and for a one-off file, enriching a CSV matches each row on the enterprise or VAT number.
The Dutch counterpart: the KVK number, RSIN and VAT ID.
Frequently asked questions
How do I find a Belgian company's enterprise number? Search the company name in KBO Public Search, free and without an account, and narrow the results by postal code. It also appears on the company's invoices, letters and website.
Is the enterprise number the same as the VAT number? The digits are the same: BE0202239951 belongs to enterprise number 0202.239.951. But only entities subject to VAT have a VAT number; KBO Public Search shows "Subject to VAT" when that applies.
Why does a Belgian enterprise number start with 1? The series starting with 0 ran out. The first number starting with 1 was issued on 19 September 2023; older companies keep their 0 number.
How do I check whether an enterprise number is valid? Divide the first eight digits by 97 and subtract the remainder from 97; the result must equal the last two digits. That proves the number is well-formed, not that it exists. Only the KBO register confirms that.
Photo: a street sign on the Place Saint-Lambert in Liège, FrDr, CC BY-SA 4.0, via Wikimedia Commons