What to declare depending on the type of let
The tax regime depends on how the property is used. Private let (housing): declare the non-indexed CI in Part III of the PIT return. Professional let or let to a company: declare the actual gross rent reduced by a flat-rate expense deduction of 40% (capped at indexed CI x 2/3). The actual rent is always more heavily taxed.
| Situation | What to declare | PIT code |
|---|---|---|
| Let to a private individual (housing) | Non-indexed CI | Part III, box 1106/2106 |
| Let to a company or professional use | Actual rent - 40% | Part III, box 1109/2109 |
| Unlet property (own use) | Non-indexed CI | Part III, box 1100/2100 |
Where and when to declare
The declaration is made annually via Tax-on-web (online) or on the paper PIT form. The filing deadline is typically late June for paper returns and mid-July for online filings. Each property must be declared separately in Part III of the return.
You own an apartment let to a private individual for EUR 900/month. CI = EUR 1,000. In your PIT return, you only declare the non-indexed CI of EUR 1,000. The tax authorities apply the indexation coefficient and the 40% increase automatically.
Special cases
Mixed use: if the lease does not specify a split between private and professional use, the administration may tax 100% as professional rental (on actual rent). Always include a clear split clause in the lease.
Multiple properties: each property must be declared individually with its own CI and usage regime.
Foreign properties: Belgian residents must declare income from foreign properties (actual rent or rental value minus expenses) in Part III as well.
Failure to declare rental income can result in a tax surcharge of 10 to 200% of the evaded tax. The statute of limitations is 3 years (7 years in case of fraud).
For a property let to a company, always split the rent between private and professional portions in the lease to avoid full taxation on the actual rent.
Regional specifics
Brussels-Capital Region
No specific regional variation for the declaration of rental income. The federal PIT rules apply uniformly. Brussels Fiscalite manages property tax separately.
Walloon Region
Same federal PIT rules apply. Wallonia does not impose additional regional taxes on rental income beyond the property tax.
Flemish Region
Same federal PIT rules apply. Flanders applies its own additional surcharges to the PIT through the Flemish personal income tax component.
Articles 7 to 13 CIR 92 (rental income taxation), Tax-on-web — Texts on Justel