The short answer
KYC (know your customer) and KYB (know your business) are the identity checks that the Belgian anti-money-laundering law of 18 September 2017 requires from a closed list of "obliged entities": banks, insurers, payment and crypto firms, auditors, accountants and tax advisers, notaries, bailiffs, lawyers for certain deals, real estate agents, diamond traders and dealers in art or antiques from 10,000 euros. Belgium did not make ordinary sellers of goods obliged; instead, nobody may pay or accept more than 3,000 euros in cash. For a business customer, due diligence means identifying the company, its directors and who may bind it, its beneficial owners and the purpose of the relationship, then monitoring it. Sanctions lists apply to everyone. Any B2B seller can run the same register checks to stop fraud.
The rules below come from the consolidated law of 18 September 2017 on Justel and from FPS Finance's and FPS Economy's pages on financial sanctions and invoice fraud, read on 1 October 2026. This is general information, not legal advice.
KYC, KYB and customer due diligence
KYB is KYC applied to a company. The Belgian law uses neither acronym: it speaks of due diligence (waakzaamheid, vigilance), in three parts (article 19): identify and verify the customer, assess the customer and the purpose of the relationship, and keep watching it. All of it is risk-based, with enhanced measures for high risk and simplified ones for low risk.
Who is obliged under the law of 18 September 2017
Article 5 lists the obliged entities. The main groups:
Financial sector. The National Bank, bpost's financial services, banks, life insurers, payment and e-money institutions, investment firms, crypto-asset service providers, lenders, leasing companies and insurance intermediaries.
Audit, accounting and tax. Registered auditors, accountants and tax advisers, including tax advisers outside the professional institute.
Legal professions. Notaries, bailiffs and company service providers. Lawyers when they help a client buy or sell real estate or a business, manage client money, or set up or run companies or trusts.
Real estate. Registered real estate agents.
Goods and other activities. Diamond traders; dealers and brokers in works of art or goods over fifty years old when the price is 10,000 euros or more; professional football clubs and agents; safe-deposit renters; certain security firms; gambling operators.
What about sellers of goods who take cash? Belgium does not list ordinary traders in goods. It caps cash for everyone instead. Article 67 bans any cash payment above 3,000 euros for one transaction or a set of transactions that appear linked, whatever the total price. Business buyers may not pay cash for copper cable at all, and the price of real estate may only be paid by transfer or cheque (article 66).
What due diligence on a company requires
An obliged entity runs these checks when it enters a business relationship, and for occasional transactions of 10,000 euros or more (article 21).
Identify the company. Name, registered office, list of directors and the rules on who can bind it (article 26), verified against documents or reliable, independent sources (article 27). The enterprise number ties these sources together, and finding who runs a Belgian company shows where directors appear.
Identify the beneficial owners and understand the ownership and control structure (article 23). Holding more than 25% of the shares or voting rights, directly or through controlled companies, is an indication of ownership (article 4). Listed companies are exempt.
Use the UBO register, but not alone. For a new relationship, collect proof of the customer's UBO registration or an extract, and take further measures in line with the risk (article 29).
Assess the customer and the purpose, including whether a director or owner is a politically exposed person (article 34). A PEP needs senior management approval, a check on the source of funds and closer monitoring (article 41).
Monitor transactions against the customer's profile and keep the data up to date (article 35).
Keep the records for ten years after the relationship ends (article 60).
If the checks cannot be completed, the obliged entity may not start the relationship, and must consider a report to the Financial Intelligence Processing Unit (CFI/CTIF) (article 34). For a broader review before a large contract or an acquisition, see how to run due diligence on a Belgian company.
Checks and where to find them
Check | What to look at | Source |
|---|---|---|
The company exists and is active | Legal name, legal form, status, registered office | KBO Public Search, free |
Enterprise and VAT number | Well-formed number, active VAT registration | KBO; VIES for the VAT number |
Directors | Current mandates and start dates | KBO functions; Official Gazette |
Who may bind the company | Representation clause, daily management | Statutes; Official Gazette |
Beneficial owners | Natural persons above 25% or in control by other means | UBO register (obliged entities, or a legitimate interest) |
Ownership and group | Shareholder structure, participations, foreign parents | Annual accounts filed with the National Bank |
Sanctions | Company, directors and owners against freeze lists | Treasury consolidated list (EU, UN and Belgian measures) |
Politically exposed persons | Prominent public functions of directors and owners | The functions are listed in an annex to the law |
Changes over time | New directors, seat transfers, mergers, insolvency | Official Gazette; KBO status |
The UBO register: role and access
The Treasury of FPS Finance keeps the UBO register (article 73) to help prevent money laundering and terrorist financing, to support sanctions and asset freezes, and to make companies, non-profits and trusts transparent to the authorities (article 74). Under article 75, authorities have full access, obliged entities have access for their due diligence, and anyone else must demonstrate a legitimate interest, for the data set by royal decree. Consultation is free. Obliged entities must report differences between the register and what they know to the Treasury (article 74/1). The Belgian UBO register guide covers who must register, the fines and how public access was closed.
Sanctions screening applies to everyone
Financial sanctions are not limited to obliged entities: FPS Finance states that everyone in Belgium must observe them. A freezing measure has two sides: the assets of a listed person or entity are frozen, and no funds may be made available to them. The measures come from the UN, the EU and a Belgian national terrorism list, and the Treasury publishes a consolidated list of everyone under freezing measures in Belgium.
Not obliged? The same checks still stop fraud
Most B2B sellers are not obliged entities. Their risk is goods or services delivered on credit to a company that does not exist, or is not who it claims to be.
Borrowed identities. An order in a real company's name from an unknown email domain. Check the enterprise number in the KBO, compare name and address, and call back on a number from the company's own website. A valid VAT number proves less than it seems.
Invoice fraud. FPS Economy describes fraudsters who intercept an invoice, change the bank account and send it on. In the reports it received in 2016, invoices averaged 14,000 euros, ranging from 1,600 to more than 55,000. Compare the account number with the order form or official website, distrust any "changed account number" notice, call a number you already know, and report at meldpunt.belgie.be.
Sudden changes in the Official Gazette. A new registered office and new directors published in the last few weeks, followed by a large first order on credit, deserve a closer look before you ship. How to search the Official Gazette.
Letters that look official. FPS Economy warns about requests to "correct" company data that sign you up to an expensive multi-year contract, and invoices for contracts never signed.
For Belgian companies, Bizzy puts the register side of these checks on one record: identity from the KBO (legal form, VAT number, establishments), directors, Official Gazette documents filterable by type, and a group structure and shareholders view with percentages and countries. That ownership comes from filings, not the UBO register, and Bizzy is not an AML or KYC compliance tool: it does no sanctions or PEP screening. See plans, with a free start.
Frequently asked questions
Is KYC mandatory for every Belgian company? No. The due diligence duties apply only to the obliged entities in article 5 of the law of 18 September 2017. The 3,000 euro cash limit and financial sanctions apply to everyone.
What does KYB involve for a Belgian company? Identifying the company by name, registered office, directors and who may bind it, identifying its beneficial owners, assessing the purpose of the relationship and monitoring it.
Can a supplier consult the UBO register? Only by demonstrating a legitimate interest under the conditions set by royal decree. The shareholder structure in the annual accounts filed with the National Bank is public.
What is the cash payment limit in Belgium? 3,000 euros per transaction or set of linked transactions, whatever the total price, except between consumers. Real estate may only be paid by transfer or cheque.
Photo: the Walloon Parliament and the citadel of Namur at night, NEW - Namur, CC BY-SA 4.0, via Wikimedia Commons