Setting Your Company's Financial Year in Belgium: A Guide for New Founders
- Jul 15
- 6 min read
Updated: Jul 16
Every company registered in Belgium must have a financial year — a fixed period that forms the basis for its accounting, tax filings, and annual reporting. While this might sound like a formality, the way a financial year is defined and structured has real consequences: it determines when you file your annual accounts, how your tax base is calculated, and even whether your company qualifies as "small" or "large" under Belgian law.
For new entrepreneurs in particular, understanding how the financial year works — including when it can be shorter or longer than 12 months — helps avoid confusion during incorporation and keeps your company compliant from day one.
What Is a Financial Year?
A financial year (in Dutch: boekjaar; in French: exercice) is the accounting period over which a company prepares its financial statements. At the end of each financial year, a company must close its books, draw up annual accounts, and report its results — both to the tax authorities and, in most cases, to the National Bank of Belgium.
Financial Year vs Calendar Year
A financial year does not have to match the calendar year. Many companies do align their financial year with the calendar year, running from January 1st to December 31st, simply because it's straightforward and matches the tax year. But Belgian law gives companies the flexibility to choose a different 12-month period — for example, from July 1st to June 30th — based on what suits their business cycle best.
What Is the First Financial Year of a New Company?
When a company is incorporated, its first financial year doesn't automatically run for exactly 12 months. It starts on the date of incorporation and ends on whatever closing date is chosen in the company's articles of association.
This means the first financial year can be:
Shorter than 12 months — if the company is incorporated partway through the year and the founders choose to close the books at the "normal" year-end shortly after.
Longer than 12 months — if the founders prefer to push the first closing date further out, giving the company more time before its first annual accounts are due.
Example: A company is incorporated on September 1st, and its articles of association set the standard year-end at December 31st. The founders can choose to close the first financial year on December 31st of the same year (a short first year of 4 months), or extend it to December 31st of the following year (a long first year of 16 months).
Can a Financial Year Be Longer or Shorter Than 12 Months?
Yes — not just for the first financial year, but in specific circumstances afterward too. Belgian company law allows a financial year to deviate from the standard 12-month period, within certain limits.
Extended Financial Year (Verlengd Boekjaar)
An extended financial year runs for more than 12 months. This typically happens when:
A company wants to change its year-end date and needs a transitional period to bridge the old and new closing dates.
The first financial year is deliberately stretched to delay the first round of annual reporting.
Maximum duration: Under the Belgian Companies and Associations Code (CSA), a financial year — including an extended one — can never exceed 24 months minus one calendar day.
Shortened Financial Year (Verkort Boekjaar)
A shortened financial year runs for less than 12 months. Common situations include:
A newly incorporated company choosing to align quickly with a "normal" year-end.
A company changing its financial year-end and shortening the current year to transition to the new date.
Dissolution or liquidation, where the final financial year ends earlier than planned.
What Is a Non-Calendar Financial Year (Gebroken Boekjaar)?
A non-calendar financial year (gebroken boekjaar in Dutch, sometimes translated as "broken financial year") is a financial year that still lasts exactly 12 months, but does not align with the calendar year. Instead of running from January 1st to December 31st, it might run, for instance, from April 1st to March 31st.
This is a different concept from an extended or shortened financial year. A gebroken boekjaar is a financial year that does not follow the calendar year. In practice, it is often a standard 12-month period, but it may also be combined with an extended or shortened financial year during transitional periods.
Why Some Companies Choose a Different Year-End Date
Companies sometimes opt for a non-calendar financial year because it fits their business activity better. For example:
A retail business with a peak season around the December holidays may prefer closing its books in a quieter month, such as June, to make stocktaking and year-end accounting easier.
A company whose parent group abroad uses a non-calendar reporting cycle may align its Belgian subsidiary's financial year with the group's for consolidation purposes.
How Does a Financial Year Affect Company Size Criteria?
Company Size Classification in Belgium
Belgian law classifies companies into categories — micro, small, and large — based on three criteria: balance sheet total, net turnover, and average number of employees. The category a company falls into determines its accounting and disclosure obligations, including whether simplified reporting is allowed.
Impact on Turnover Thresholds
When a financial year is shorter or longer than 12 months, the turnover figure used to assess these size criteria can't simply be compared as-is to the standard annual thresholds. Instead, Belgian law requires the threshold itself to be adjusted proportionally: the standard turnover threshold is multiplied by a fraction where the denominator is 12, and the numerator is the number of months covered by that financial year.
This adjustment ensures that a company with, say, a 6-month financial year isn't unfairly classified based on only half a year's turnover, and that a company with an 18-month financial year isn't penalized for an unusually high cumulative figure.
Did You Know?
Any month that has started — even by a single day — counts as a full month when calculating this adjustment. The Belgian Accounting Standards Board (CNC/CBN) has clarified that the number of months to use is based on the actual elapsed period of the financial year, not simply the number of calendar months touched by it.
For example: a company that normally closes its accounts on December 20th decides, exceptionally, to extend its financial year until February 15th of the year after next. That period spans 13 months and 26 days. Because the remaining 26 days form part of a new month that has "started," it counts as a full month — bringing the total to 14 months for the purposes of the turnover adjustment.
Can You Change Your Financial Year?
Basic Requirements
Yes, a company can change its financial year-end date. This typically requires:
An amendment to the company's articles of association, since the financial year-end is specified there.
A decision taken in line with the company's standard procedure for amending its articles (usually involving a general meeting of shareholders).
Filing the updated articles of association with the relevant registries.
The transition between the old and new year-end is achieved through either a shortened or an extended financial year, depending on the direction of the change.
When Changing the Financial Year May Make Sense
Reasons to change a financial year-end include:
Aligning with a parent company's or group's reporting cycle for easier consolidation.
Moving the closing date away from a busy operational period.
Better matching the financial year with the company's natural business cycle (e.g., a seasonal business).
FAQ
Is a financial year the same as a calendar year? Not necessarily. A financial year is always 12 months in normal circumstances, but it doesn't have to run from January 1st to December 31st. Many Belgian companies do align the two, but it's not a legal requirement.
How long can the first financial year be? The first financial year of a newly incorporated company can be shorter or longer than 12 months, as long as it doesn't exceed 24 months minus one calendar day in total.
Can I choose my own financial year? Yes. The financial year-end date is set out in the company's articles of association, and founders have flexibility to choose a date that suits their business, whether that aligns with the calendar year or not.
Does an extended financial year affect company size criteria? Yes. When a financial year is longer or shorter than 12 months, turnover must be proportionally adjusted using a fraction based on the number of months in that financial year, with any started month counting as a full month.
Conclusion
The financial year is more than a bureaucratic detail — it shapes how and when a Belgian company reports its results, pays its taxes, and is classified under size criteria. Whether you're setting the first financial year for a newly incorporated company or considering a change to your year-end date, understanding the rules around shortened, extended, and non-calendar financial years helps you make informed decisions and stay compliant.
Ready to set up your Belgian company the right way? Start your incorporation online with BelDoc and let us guide you through every step — including choosing the financial year that works best for your business.
