Rental income in Belgium: how is it taxed?

Letting to a private individual: the cadastral income

Cadastral income (revenu cadastral / kadastraal inkomen, RC) is a notional income meant to represent the theoretical annual rent of the property. According to notaire.be, the current values are based on the rental income of 1975 and are indexed every year. To learn more about this concept, read our guide on cadastral income.

When the property is let to a private individual for their private use, Wikifin explains the method:

1. You declare the non-indexed cadastral income (the administration calculates the indexation).
2. The taxable income is the indexed cadastral income, increased by 40%, that is multiplied by 1.4.
3. This amount is added to your other income and taxed at your highest rate, at most 50%.

The actual rent does not enter the calculation: you can let for €900 or €1,500 a month, the basis remains the cadastral income.

A worked example

Wikifin gives this example for 2026 income, with a non-indexed cadastral income of €1,000 and an indexation coefficient of 2.3:

This last amount is a maximum: the actual tax depends on your band. The coefficient changes every year.

Letting to a business

If the tenant uses the property for business purposes, the regime is different. Wikifin states that you declare:

• the non-indexed cadastral income;
• all the gross annual rents, rental benefits included.

The taxable amount corresponds to the rents minus a flat-rate 40% for expenses, with a limit that Wikifin does not quantify. It is taxed at the marginal rate, up to 50%. To know the limit and the exact calculation for the year, consult FPS Finance or your accountant. The official FPS Finance page could not be consulted at the time of writing: do not rely on any limit amount from this guide.

The other taxes on a let property

Property tax

In both cases, property tax (précompte immobilier / onroerende voorheffing) is due every year. It is calculated on a percentage of the cadastral income, to which the municipal, provincial and conurbation surcharges are added. See property tax. Wikifin does not give the base percentage.

Furnished lettings

According to Wikifin, the property part follows the rules above. Part of the rents is declared as income from movable property, subject to a withholding tax on movable income (précompte mobilier) of 30%.

The capital gain on resale

If you sell the property less than 5 years after the purchase, the capital gain is taxed at 16.5%. Beyond 5 years, it is not taxed. For a property received as a gift (and not through an inheritance), the period is 3 years. See also capital gains on property.

A property that is not let

For a second home that you occupy yourself, Wikifin gives the same basis: the indexed cadastral income increased by 40%. If the property is neither let nor your home, the commune may also apply a tax (see second-home tax).

What to declare, and where?

Your non-indexed cadastral incomes can be found on MyMinfin, according to Wikifin. For the lease, see lease registration and, for changes in the rent, rent indexation.

Which professional to consult

An accountant or a tax adviser can check your return and tell you which regime applies to your letting, especially if the tenant is a company or a self-employed person. For a question about the amount of the cadastral income, the Cadastre administration is competent. A notary can advise you on the purchase, the sale and the capital gain.