01
Availability date
It determines the allowance band. Keep the deed and evidence of actual occupation.
Luxembourg 2026Official tax source
Estimate the Luxembourg mortgage-interest deduction
Calculate the limit applying from the date your main home became available and the number of people in the tax household.
Calculate my tax saving- Maximum deduction
- Unlimited, then €4,000 / €3,000 / €2,000 · per household member according to years of occupation
- Potential saving
- Potentially high at the start of the loan
- Main condition
- Owner or future owner of a dwelling used for personal needs, subject to the applicable conditions.
- Term / liquidity
- No lock-in; limit follows the occupation date
Enter only eligible interest and costs after interest subsidies. Repayment of loan principal is not deductible.
2026 calculator
Estimate the mortgage-interest deduction
Enter interest actually borne after subsidies and select the period since the home became available.
Method and limitations
The engine applies the legal ceiling, calculates the additional reduction in taxable income, then reuses the progressive 2026 scale and employment-fund surcharge. It does not simulate an ACD decision, foreign taxation or future product taxation.
Comparison scope
Why mortgages are not ranked here
A valid mortgage comparison needs equivalent rates, term, loan-to-value, guarantees and borrower profile. This page measures the tax deduction rather than ranking headline rates.
No artificial ranking
This is deliberate: the available data is not sufficiently comparable or the taxpayer does not choose the provider directly. The criteria below remain the relevant checks.
Decision
Four checks before deciding
Request a quantified written answer where a product exists. Marketing material does not replace full terms, complete fees or a suitable proposal.
02
Net interest
Subtract interest subsidies and never include principal repayments.
03
Tax-household size
After the initial years, the ceiling is multiplied by the people taken into account for tax.
04
Personal use
Different rules apply to rented property, second homes or business use.
Analysis
Who is it for, why use it and what goes wrong?
Potentially suitable if…
- An owner-occupier or buyer during construction paying eligible interest.
- A household checking the limit that corresponds to its occupation year.
Less suitable if…
- A buy-to-let investor, whose interest follows rental-income rules.
- A borrower attempting to deduct principal repayments.
Common mistakes
- Entering the full instalment instead of interest only.
- Including an interest subsidy already reimbursed.
- Using the loan date rather than the date the home became available.
Advantages
- + No ceiling during construction and the first two occupation years.
- + The later ceiling is multiplied by household members.
- + Reduces taxable income within the applicable limit.
Drawbacks
- − The deduction decreases over time.
- − Interest subsidies must be subtracted.
- − Mixed-use property requires a more complex analysis.
Worked example
Example: three people in the fourth year after occupation
In the €4,000-per-person band, the limit is €12,000. If €9,500 of net interest was paid, €9,500 is considered; if €14,000 was paid, the deduction is capped at €12,000.
2026 rules
What the calculator includes
- Before the dwelling is available, eligible interest and certain borrowing costs are deductible without a ceiling.
- Interest remains uncapped in the year the dwelling becomes available and the following year.
- The ceiling is then €4,000 per person for the next five years, €3,000 for the following five and €2,000 thereafter.
- Interest subsidies reduce the deductible expense.
- The calculator covers only a personally occupied home, not rental income.
Frequently asked questions
FAQ Mortgage interest
Can mortgage instalments be deducted?
No. Only the interest portion and certain eligible costs qualify; principal repayment does not.
When is mortgage interest uncapped?
Before the home becomes available, then in the availability year and the following year, subject to the applicable conditions.
Do children increase the interest ceiling?
Yes, when they are included for the relevant tax-household increase.
Must an interest subsidy be deducted?
Yes. The subsidy reduces the interest actually borne and therefore the deductible expense.
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