🇧🇪 How to prepare for a Tax Audit in Belgium

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A tax audit doesn’t necessarily mean you did something wrong, it simply means the administration wants to take a closer look at your numbers.

We’ve created this step-by-step guide to help you approach an audit calmly and confidently.

1. 📨 Read the audit letter carefully

2. 📂 Gather the requested documents

3. 🔎 Double-check everything (Yes, even triple-check!)

4. 🤝 Be transparent and cooperative

5. 🗂️ Stay organised during the audit

6. ✅ After the audit

7. 💼 Stay audit-ready all year round

⚙️ The modern tax audit

Belgian tax audits have changed. Instead of an inspector showing up with binders and checklists, you’ll often receive digital questionnaires with very specific requests.

The tax administration now uses data mining and algorithms to detect irregularities by comparing your VAT returns, income declarations, social data, and even banking information.

💡 What this means for you:

• Audits are now more focused and data-driven.

• You’ll be asked for precise documents or explanations, not general overviews.

• Keeping your accounting digital, structured, and transparent is the best way to stay audit-ready.

1. 📨 Read the audit letter carefully

The first thing you should do is understand exactly what the administration is asking for.

Look for:

• The period under review (e.g., 2022 income year)

  • For personal income tax or corporation tax: typically 3 years after the tax year; extended to 7 years if fraud is suspected.

  • For VAT: generally 3 years, or 7 years in case of suspected fraud.

• The taxes concerned: VAT, personal income tax (impôt des personnes physiques / personenbelasting), or both

• The documents requested

• The submission deadline

2. 📂 Gather the requested documents

In Belgium, auditors usually ask for:

• Your issued and received invoices

• Proof of payments (bank statements)

• Expense receipts and other supporting documents

• VAT returns and the annual client listing

• Income tax returns and accounting records

The auditor is entitled to request all documents necessary to determine your taxable income including digital data such as emails or stock lists.

For VAT audits, bank statements are often checked; however, VAT auditors generally need special authorisation to access certain financial information (such as private bank accounts).

If you use Accountable, most of these are already organised for you. Simply go to the related VAT quarter (for instance, Q3 of 2025) → go to ‘Submission’ → click on ‘download’ → select the file-type you want to export.

3. 🔎 Double-check everything (Yes, even triple-check!)

Before you send anything, make sure your data is consistent and complete:

• Totals in your invoices (excl. VAT if apply) match your declared income

• Every expense is backed up by a valid document

• VAT is applied and reported correctly

• Business and private transactions are clearly separated

📘 Why this matters:

Small inconsistencies can trigger additional questions or delays. Showing clean, well-structured data creates trust and helps your audit go smoothly.

In personal income tax or corporation tax audits, the authorities can correct obvious material errors themselves (for example, simple arithmetic or transcription mistakes not interpretation or missing data).

4. 🤝 Be transparent and cooperative

Auditors from SPF Finances appreciate honesty and professionalism.

If you made an honest mistake, explain it clearly and provide the corrected figures or documents.

5. 🗂️ Stay organised during the audit

If the audit happens on-site or digitally, structure your files by year and category.

When additional information is requested, provide it promptly.

6. ✅ After the audit

Once the audit is completed, the tax administration (SPF Finances / FOD Financiën) may send you different documents depending on the findings.

Here’s how to understand them 👇

🧾 If you receive a Statement of Findings (Procès-verbal de constatation / Verslag van vaststelling)

This is an official report summarising what the auditor observed — inconsistencies, missing documents, or factual findings.

It serves as evidence but does not yet change your tax position.

You can:

• Review the findings carefully and send explanations or missing documents

• Correct any mistakes voluntarily

• Note that the tax office may use this Statement of Findings later to support administrative fines (mainly in VAT cases)

✉️ If you receive a Proposed Adjustment (Proposition de rectification / Kennisgeving van wijziging)

If the administration intends to modify your tax declaration, they will send a written proposal explaining why.

You then have two options:

• ✅ If you agree: sign the proposal and pay any additional tax (plus possible late-payment interest).

• ❌ If you disagree: you can refuse to sign and have 30 days to respond in writing with your explanation or evidence.

If you don’t respond within that one month, the administration may proceed to an official assessment (“aanslagbiljet”) based on the information they have.

If the disagreement continues, the administration may issue a Tax Assessment Notice (Avertissement-extrait de rôle / Aanslagbiljet).

From that moment, you have 6 months to file an administrative appeal (Réclamation / Bezwaar).

You can later go to court if needed, though this is rarely necessary.

📊 Summary of audit outcomes

🗣️ Documents are usually sent in the taxpayer’s official language (French, Dutch, or German).

7. 💼 Stay audit-ready all year round

You can’t always prevent a tax audit, some are random, but you can stay ready:

• Keep business and private transactions separate (ideally different bank accounts)

• Attach supporting documents to each expense in Accountable

• Review your VAT returns before submission (easy with the tax checks done automatically)

• Regularly export your documents and keep backups

Because auditors can ask for documents going back up to 3 years, and up to 7 years in cases of suspected fraud, you should keep good records for at least that duration.

📁 With Accountable, your records are digitally stored, timestamped, and organised, which means you’re always prepared if the tax office comes knocking.

In need of further assistance, don't hesitate to contact us on

tax-coach@accountable.eu 💜

Author - Valesca Wilms

As content marketing lead at Accountable Belgium, Valesca writes about freelancing, self-employment, and taxes based on her own experience as a freelancer.

Who is Valesca ?