How does a tax audit work (Belgium) – what can the tax authorities ask for?.

Details

• Source: https://www.accountable.eu/nl-be/blog/belastingcontrole/
• Last updated (source): 17 June 2026

Summary

• A tax audit is usually announced in advance (a letter with the timing, location, period, and what will be audited).
• The auditor may request documents, but it is not a search: they cannot just snoop around your office/computer (unless there are strong indications of fraud + an appropriate authorization).
• You must be able to substantiate income and expenses with, among other things, purchase invoices, receipts, sales invoices, and bank statements.
• The tax authorities can usually go back up to 3 years; in case of suspected fraud even up to 7 years.

How does a tax audit work?

1. You will usually receive an announcement letter with practical information.
2. If the proposed date does not work, get in touch quickly (e.g., to arrange for your accountant to be present).
3. The audit can also happen unexpectedly, but only during office hours. The auditor must be able to show the reason and identity.
4. You provide the requested documents. The smoother your cooperation, the sooner the audit will be completed.

What can the tax authorities check / request?

Make sure you can quickly show the following for the requested period:

• Purchase invoices
• Receipts / supporting documents
• Sales invoices
• Bank statements

Tip: use a business bank account for your business. If many business expenses run through your personal account, that account may also become relevant.

Point of attention: mixed and private expenses

• The tax authorities will check, among other things, whether private expenses were recorded as business expenses.
• For mixed expenses (e.g., restaurant expenses), it helps to be able to explain the business context.
  • Note (on the receipt or in your administration) who you met with and what you discussed.
  • Keep supporting arguments for expenses you are unsure about.

What if expenses are rejected?

• If the tax authorities dispute the business nature of an expense, you may receive a proposal to settle: you then pay the additional tax (often with interest).
• You are not obliged to sign. If you refuse, this is usually followed by a notice of adjustment, to which you can respond within a month with your arguments.
• After that, (in exceptional cases) court proceedings are still possible, but this is often not worth the cost.

Who gets audited?

• In principle, anyone can be selected.
• There are also automatic checks (e.g., whether income/expenses deviate from sector patterns), which can cause some files to “stand out” more often.

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