Deducting mortgage interest in Belgium
Is your mortgage interest deductible in Belgium? Conditions, calculation, ceiling, and impact on rental income.
The principle of mortgage interest deduction
Mortgage interest is deductible from the owner’s property income. This is the only real deduction available for a property rented to an individual (where all other costs are covered by the RC flat rate).
| Deduction | Rented to an individual | Rented to a company |
|---|---|---|
| Mortgage interest | Yes | Yes (also within actual costs) |
| Other costs | RC flat rate (no real deduction) | Actual costs deductible |
Interest is deducted from total property income (all properties combined), not only from the income of the financed property.
For complete tax deductions, consult our dedicated guide.
The higher the mortgage interest, the lower the taxable property income. This is why borrowing to invest (rather than paying cash) is fiscally optimal in Belgium.
Deductibility conditions
The loan must:
- Be taken out to acquire, build or renovate a property generating income
- Be taken out with a financial institution in Belgium or Europe (not a family loan without a deed)
- Be secured by a mortgage or a mortgage mandate (not a personal loan)
Deductible interest includes:
- Normal interest on the mortgage loan
- Late interest (if applicable)
- Outstanding balance insurance premiums if linked to the loan (debated — consult an accountant)
NOT deductible:
- Principal repayment (only interest is deductible)
- Loan processing fees
- Early repayment penalties
- Interest on a personal loan (non-mortgage)
Proof
The financial institution sends an annual form 281.61 detailing the interest paid. This is the document the tax authorities use to verify the deduction.
Calculation and optimisation
Deduction mechanism
Interest is deducted from total property income:
| Element | Amount |
|---|---|
| Property income (indexed RC x 1.40) from all properties | 5,000 EUR |
| Mortgage interest | -4,200 EUR |
| Net property income | 800 EUR |
| Tax (marginal rate 50%) | 400 EUR (instead of 2,500 EUR without interest) |
| Tax saving | 2,100 EUR/year |
Optimisation: maximise borrowing
| Strategy | Tax effect |
|---|---|
| Borrow 100% of the price | Maximum interest = maximum deduction |
| Extend the duration (25-30 years) | Higher total interest (but lower monthly payments) |
| Refinance at a lower rate | Beware: lower interest = lower deduction |
| Borrow for works | Additional deductible interest |
Limitations and pitfalls
Excess is lost
If interest exceeds property income, the difference is lost:
- Interest: 7,000 EUR
- Property income: 5,000 EUR
- Lost excess: 2,000 EUR (no carry-forward to professional income)
Solution: own multiple properties
With 2 properties, property income increases and absorbs more interest.
No capital deduction
Principal repayment is never deductible from property income. Only interest is. This is why a bullet loan (capital repaid at maturity) maximises the annual deduction.
A rental management software can integrate this data. To create a lease, use our online generator. For complete rental taxation, consult our guide.
Frequently asked questions
-
Yes. Interest on a mortgage taken out to acquire a property is deductible from immovable income. This is the only actual deduction available for a property rented to an individual.
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Yes, if the works concern a property generating immovable income and the loan was taken from a financial institution. The interest is deductible in the same way as acquisition loan interest.
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The excess is lost. Interest can only be deducted from immovable income, not from professional or movable income. It is therefore preferable to have several properties to maximise the deduction.