Invoices are essential commercial documents confirming the supply of goods or services. To deduct VAT, two conditions must be met:

1. Substantive – the goods/services are used for taxable activities.
2. Formal—the taxpayer possesses a correctly issued invoice containing mandatory elements (Article 5, §1 of Royal Decree No. 1).

A properly issued invoice safeguards both supplier and customer. Missing or incorrect invoice details can lead to penalties or loss of VAT deduction rights, potentially damaging commercial relationships.

Mandatory E-Invoicing from 1 January 2026

From 2026, structured electronic invoicing becomes mandatory for B2B transactions between Belgian VAT-registered businesses. The structured format (XML, compliant with EN 16931) replaces paper or PDF invoices for these transactions. However, all existing invoice requirements (content, language, currency) remain fully applicable.

An e-invoice must include:

• A clear description of goods/services and quantities.
• Taxable amount and VAT amount (the VAT must be shown in euros; if another currency is used, it must be converted using the agreed or official rate).
• For credit notes: reference to the corrected invoice and mention of VAT refunds where applicable.

Language Requirements: The law doesn’t prescribe a specific language, but VAT authorities may request a translation if it’s not in a national language. Other legal frameworks (like language legislation) also apply.

Risk of Deduction Refusal for Improper Invoices

Courts have confirmed: VAT is non-deductible if invoices lack required information, such as service details, work dates, or supporting documentation (contracts, emails, etc.).
For example:

• The Antwerp Court of Appeal denied a deduction due to vague descriptions and unrealistic hours, issuing a 200% fine.
• The Ghent Court of Appeal reaffirmed that incomplete descriptions without contractual evidence invalidate deduction claims.

General terms or vague wording are not enough—you must be able to demonstrate the actual supply of goods or services with proper documentation.

Substance over Form—But with Limits

The EU Court of Justice supports the principle of “substance over form”: VAT deduction shouldn’t be denied solely on formal grounds if substantive conditions are met. This is recognised in Belgian circular 2017/C/64. Still, incomplete or suspicious invoices may lead to denied deductions and fines, particularly if supporting documents are also lacking.

Direct Tax Considerations

For direct tax deductibility, costs must be supported by authentic documentation. The Ghent Court recently denied deduction for vague invoices with no proof of service validity. Businesses should request corrected invoices if descriptions are unclear.

E-Invoicing: Scope and Penalties

From 2026, structured e-invoicing will be legally required for:

1. B2B transactions between VAT-registered businesses in Belgium (excluding foreign/non-established or exempt entities).
2. Customers established in Belgium who file VAT returns and provide a valid VAT number.
3. Domestic transactions subject to Belgian VAT, including reverse charge transactions.

Exemptions: Entities only performing exempt activities (e.g., financial, educational, and healthcare sectors), flat-rate taxpayers (until 2028), and cross-border transactions.

Penalties:

• Suppliers not issuing compliant e-invoices: fines between 60–100% of the VAT.
• Customers unable to receive/process e-invoices lose VAT deduction rights, even if a PDF invoice is provided.
• Incorrect VAT deduction: a 10% fine applies.

While there is currently no additional liability for customers failing to receive e-invoices, the risk to VAT deduction remains significant.