1. Treating Benelux as one VAT market and assuming OSS covers everything.
OSS is optional, split across Union, non-Union, and Import schemes, and the €10,000 EU-wide threshold only applies to certain cross-border B2C TBE services and intra-EU distance sales of goods, and only for businesses established in one Member State. Companies often overextend OSS and miss that it does not replace local VAT handling for every Benelux transaction pattern.

2. Missing local registration triggers once stock, domestic sales, or own-goods movements are involved.
This is one of the biggest entry mistakes. Belgium says non-Belgian companies must register if they carry out Belgian transactions on which they themselves owe Belgian VAT; Luxembourg generally requires registration where a non-established business makes supplies taxable in Luxembourg, except OSS cases; and the Netherlands says foreign entrepreneurs must register in many situations. Moving your own goods into stock in another Member State normally also creates destination-country VAT obligations unless a simplification, such as valid call-off stock, actually applies.

3. Applying the wrong place-of-taxation or assuming reverse charge always applies.
For goods, domestic supplies without transport are taxed where the goods are located; distance sales are generally taxed where transport ends; and installation supplies are taxed where installation happens. For services, B2B is generally taxed where the customer is established and B2C where the supplier is established, but there are important exceptions for immovable property, event admission, catering, and short-term vehicle hire. The Dutch tax authority also makes clear that reverse charge may apply in cross-border cases, but not as a universal shortcut.

4. Zero-rating intra-EU sales without the transport evidence, VAT-number checks, and companion reporting needed to support the 0% treatment.
In practice, companies still fail to validate customer VAT numbers through VIES or forget the companion reporting. In the Netherlands that means ICP; in Belgium, intra-Community statements via Intervat; in Luxembourg, recapitulative statements for qualifying goods and services. The Dutch ICP also covers certain own-goods transfers and call-off stock reporting.

5. Underestimating import-VAT cash flow and local filing/invoicing operations.
Companies entering via Rotterdam or Antwerp often forget that import VAT can become a financing problem unless they set up the local deferment mechanism. The Dutch Article 23 system lets import VAT be settled through the VAT return, while Belgium’s ET14000 postpones import VAT to the periodic return. On top of that, since 1 January 2026, Belgium has required structured e-invoicing for nearly all B2B transactions between Belgian enterprises liable to VAT, Belgium periodic VAT returns are filed through Intervat, and Luxembourg requires electronic VAT filing.