What the annual accounts contain
The balance sheet is a snapshot of what the company owns and owes on the closing date. The profit and loss account traces the activity of the financial year, from income through to profit or loss. The notes explain and break down the items that warrant it, from depreciation to off-balance-sheet rights and commitments.
The size of the company determines which model applies: micro, abridged or full. The more detailed the model, the richer the published information, and the more the filing costs.
The filing deadline
The rule comes in two steps. The general meeting approves the accounts within six months of the close of the financial year. The directors or managers then file them with the National Bank within 30 days of that approval, and never later than 7 months after the close (articles 3:1, 3:10 and 3:12 of the Code of Companies and Associations). For a financial year closed on 31 December 2025, the deadline therefore fell on 31 July 2026.
Late filing triggers a surcharge on top of the filing fee. The National Bank noted that in 2024, 39 % of filings arrived after the deadline.
Filing fees for 2026
Fees vary by model and format. For 2026, filing in XBRL costs 67,00 € for the micro model, 89,40 € abridged and 379,50 € full. In PDF, the same models come to 137,30 €, 159,50 € and 449,70 €. A corrected filing costs 86,00 € (source: National Bank of Belgium, Central Balance Sheet Office, verified on 29 August 2026).
The gap between XBRL and PDF is striking: filing a micro model in PDF costs more than double the same filing in XBRL. That alone is reason enough to ask your firm which format it uses.
What a delay costs
Late-filing surcharges applicable from 1 January 2026 are 151 € for a small company from the 9th month, 227 € from the 10th to the 12th month, and 453 € from the 13th. For a company on the full schema, the same delays cost 504 €, 755 € and 1 510 €. These amounts are indexed every 1 January.
A delay of a few months therefore often costs more than the price gap between two accounting firms. An appeal procedure exists with the National Bank.
What people often confuse
The annual accounts are not the tax return. The first is an accounting document filed with the National Bank and open to public inspection. The second is a corporate income tax return sent to the tax administration through Biztax, and it is not public.
Both rest on the same financial year and follow one another closely in the calendar, which explains the confusion. Filing fees at the National Bank are not fees for professional services either: the firm advances them and passes them on, a point covered in our guide on what an accountant costs in Belgium.