Renting out property: you are not taxed on the rent
This is the first thing to understand, and it surprises almost every new landlord: if you let a home to a private tenant who lives in it, the tax office ignores the rent you collect. It taxes the indexed cadastral income, plus 40%. A rent of €1,000 and a rent of €1,400 on the same property give you exactly the same tax bill. Here is the real calculation, and the obligations that come with it.
The whole property topic is usually written from the point of view of the person buying or the person renting. This page takes the other seat: the landlord's. And it starts with the rule that throws people the most.
Private tenant: the rent does not count
If your tenant is a private individual who does not use the property for professional purposes, the tax base is the indexed cadastral income, plus 40%. The rent you collect appears nowhere in the calculation.
Non-indexed cadastral income of €450. Indexation: 450 × 2.2446 = €1,010. Uplift: 1,010 × 1.4 = €1,414 of taxable income, for 2025 income. That amount is added to your other income and follows your marginal rate.
In your tax return you enter the non-indexed cadastral income, in boxes 1106 or 2106. The indexation and the uplift are applied automatically: you have no calculation to do.
| Income year | Assessment year | Indexation coefficient |
|---|---|---|
| 2025 | 2026 | 2.2446 |
| 2026 | 2027 | 2.3000 |
The direct consequence for an investor: for the same cadastral income, raising the rent does not raise the tax. That is what makes the gap between gross yield and net yield far more favourable in Belgium than in countries that tax the rent collected.
Business tenant: here the rent does count
As soon as the tenant is a company, a legal entity, or a private individual who uses the property professionally, the regime flips. The tax base becomes the higher of two amounts.
Cadastral income of €1,000, gross rent of €18,000. The rent net of expenses gives €10,800. The floor gives €3,143. The tax base kept is therefore €10,800, more than three times that of a let to a private tenant.
The tax return boxes are 1109 / 2109 for the non-indexed cadastral income and 1110 / 2110 for the gross rent and rental benefits.
⚠️ A clause in the lease is not enough to protect you. What counts is the actual use of the property. A tenant who registers a business address in the home can flip the regime, with retroactive effect. That is the point to check before signing, not after.
Taxation of real rents: where things stand
No text has been adopted, no date has been set, no rate exists. The regime that applies remains the indexed cadastral income plus 40% — that is what FPS Finance publishes today, and it is the only verifiable element.
Taxation of real rents appears as a long-term intention in policy documents, for property held beyond the main residence. It was not kept in the first phase of the tax reform. As long as no text is published, it has no effect on your tax return — and we will not anticipate it here.
Lease registration: free, and it is your job
| Type of lease | Deadline | Cost |
|---|---|---|
| Used exclusively as housing | 2 months | Free |
| Other leases (commercial, mixed, garage) | 4 months | 0.2% of rent and charges, min. €50 |
| Inventory of fixtures, housing | Same deadline | Free |
| Inventory of fixtures, mixed lease | Same deadline | €50 |
It is the landlord who is legally required to register. The tenant may do it voluntarily if the property is used exclusively as housing — which is what happens when the landlord neglects the formality. Registration goes through MyRent, the only legally recognised authentic source for residential leases.
⚠️ Not registering costs more than a fine. An unregistered lease is not enforceable: if the property is sold, the new owner is not bound to honour it. In Wallonia, registration is on top of that a condition for indexing the rent since 1 September 2018: no registration, no indexation, ever. We do not publish a fine amount: it is not available on any official page.
The rental deposit: two or three months
⚠️ The Flemish penalty is heavy. If the landlord holds the deposit personally, he owes the legal interest on the amount. And for contracts after 2019, the sum wrongly held may be treated as rent already paid.
Indexation, and what the EPC changes
The formula is identical in all three Regions:
The base rent is the one in the contract, excluding charges. The new index is the health index of the month before the anniversary of the lease taking effect. The starting index is the one of the month before signature — in Flanders, for leases signed since 1 January 2019, it is the month before the lease takes effect.
Indexation is never automatic: it requires a written request, and backdating is limited to three months before the month of the request. A year you forget is a year you lose.
The EPC, still active in two Regions
| Region | Status of the EPC restriction |
|---|---|
| Wallonia | Ended on 31 October 2023. Full indexation since then, with no EPC restriction. |
| Brussels | Still in force, as a correction factor, for leases that took effect before 14 October 2022 with an EPC of E, F or G. |
| Flanders | The 2022-2023 freeze has ended, but a permanent correction factor applies to later indexations for EPC D, E, F or no certificate. |
In Brussels, the correction factor only applies if the lease is registered and the EPC certificate has been given to the tenant. We do not reproduce the coefficients: they change every month and the official Brussels calculation tool is updated on the 5th of each month. Use it, rather than a frozen table.
In Flanders, the effect of the freeze is lasting: the correction factor keeps weighing on indexations in 2026 for the leases concerned. This is not an emergency measure that has run its course, it is a permanent correction.
Finally, the EPC certificate is compulsory for any home over 18 m² put up for rent. In Brussels, the administrative fine for a breach runs from €50 to €62,500.
Property withholding tax stays on you
Property withholding tax is owed by the holder of the real right on 1 January — owner, usufructuary, long-lease holder or holder of a building right. It is calculated on the indexed cadastral income, increased by municipal, provincial and agglomeration surcharges, whose rates are specific to each municipality. The simulators of Vlabel, SPW Fiscalité and Bruxelles Fiscalité give you the amount that applies.
For a main residence lease, all three Regions forbid passing the withholding tax on to the tenant, and any clause to the contrary is void. We were not able to confirm this rule on an official regional page when checking: it is well established in practice, but have it confirmed before you draft a clause. For a commercial or office lease, passing it on contractually does remain possible.