Bookkeeping obligations: what must your business do?

In brief

Every business keeps accounts. The law sets the level of detail according to your legal form and size. A small sole trader keeps a few journals. An SRL uses double entry and publishes its annual accounts. These bookkeeping obligations then shape your whole tax life.

Where do your bookkeeping obligations come from?

The foundation lies in Book III of the Code of Economic Law. It requires every business to keep accounts suited to the nature and scale of its activities. The Code of Companies and Associations adds the rules on annual accounts. Tax law then relies on those figures to calculate your taxes.

Bookkeeping obligations therefore go well beyond the balance sheet. They cover keeping the books, retaining records and several annual filings.

Simplified or double-entry accounts?

Simplified accounts

They mainly concern self-employed individuals and some partnerships. Their annual turnover must then stay at or below 500,000 euros, excluding tax. Three journals are enough.

• The purchases journal.
• The sales journal.
• The financial journal, for bank and cash.

A self-employed hairdresser with 120,000 euros of turnover can therefore stay on simplified accounts.

Double-entry accounts

SRLs, SAs and SCs must use this system. Each transaction affects at least two accounts from the standard minimum chart of accounts. The system produces a reliable balance sheet and income statement. Above the 500,000 euro threshold, a sole trader also switches to double entry.

Annual accounts

Companies draw up annual accounts at each year end. The format depends on size: micro, abbreviated or full. The criteria combine turnover, balance sheet total and average headcount. These thresholds change over time, so check the values for your financial year.

The general meeting approves the accounts within six months of the year end. Filing with the NBB follows within 30 days. Our guide to NBB filing explains the procedure and the fees.

Large companies also appoint a statutory auditor, a member of the Institute of Company Auditors. Sole traders do not publish annual accounts. Their bookkeeping obligations remain very real all the same.

Tax filings

Your bookkeeping obligations feed straight into your tax filings.

• A company files its corporate tax return every year through Biztax.
• A sole trader reports income under personal income tax.
• Any business that pays fees to third parties reports them on 281.50 forms.
• An employer withholds payroll tax on salaries and pays it over.

The standard corporate tax rate stands at 25%. Under conditions, a small company may pay 20% on its first 100,000 euros of profit. Quarterly advance payments avoid a surcharge. For a calendar financial year, they fall on 10 April, 10 July, 10 October and 20 December. Our guide to the corporate tax return goes into detail.

VAT and invoicing

A business under the standard scheme files a periodic return, monthly or quarterly. It also submits the annual listing of taxable customers before 31 March. Since 2026, its invoices to other Belgian businesses go through structured electronic invoicing.

These flows also form part of your bookkeeping obligations. Well-kept books therefore make every filing easier.

Calendar of bookkeeping obligations

Here is a typical calendar for an SRL with a 31 December year end.

• Every month or quarter: periodic return by the 20th.
• 31 March: annual listing of taxable customers.
• 10 April, 10 July, 10 October and 20 December: advance tax payments.
• 30 June at the latest: general meeting and approval of the accounts.
• Within 30 days of approval: filing of the annual accounts with the NBB.
• Date set by the FPS Finance: corporate tax return.

How long should you keep records?

Keep your books and supporting documents for the legal period. For VAT purposes, that means ten years. File them by financial year, in a readable format that nobody can alter. A tax audit can cover several past years.

What you risk

Neglecting your bookkeeping obligations comes at a high price. The Code of Economic Law provides criminal penalties for missing or irregular accounts. The tax authority can also reject your figures and assess you on the basis of indirect evidence. In a bankruptcy, poor accounts often put directors' liability at stake. Finally, a bank rarely lends without reliable figures.

Example: a new SRL

Sophie sets up a consultancy SRL in March. She hands the double-entry books to an accountant. Every quarter, she sends her purchase and sales invoices. Her accountant prepares the periodic return, then the annual accounts for the first financial year. Sophie thus meets her bookkeeping obligations without giving up her evenings.

In short

Your bookkeeping obligations depend on your legal form and size. A small sole trader keeps three journals. A company uses double entry, publishes its accounts and follows a tight tax calendar. The FPS Economy website sets out the legal framework. Want to delegate? Read how to find a Belgian accountant.