Posted on
Single-parent tax credit (CIM) in Luxembourg: complete guide for 2026
Everything you need to know about the single-parent tax credit (CIM) in Luxembourg: eligibility, amount, calculation and how to claim it on your tax return.
Raising one or more children on your own in Luxembourg can be financially demanding. Fortunately, the single-parent tax credit (CIM) can significantly reduce income tax for single parents. In this up-to-date guide for 2026, we explain who's eligible, how it's calculated and how to claim it.
What is the single-parent tax credit (CIM)?
The CIM is a direct tax benefit for single parents with one or more dependent children. Unlike a deduction (which reduces taxable income), the CIM directly reduces the amount of tax you owe.
Even better: if your tax bill is lower than the CIM amount, the difference can be refunded to you.
The CIM compensates for the absence of a second income in the household and provides concrete financial support for single-parent families.
Who can claim the CIM?
To qualify for the single-parent tax credit, you must meet all of the following conditions:
- Be classified in tax class 1a (single parent)
- Not be living as a couple (no marriage, civil partnership or legal cohabitation)
- Have at least one dependent child in your household
- The child must qualify for the child tax allowance
Important
If the child primarily lives with the other parent, you cannot claim the CIM. Only the parent who includes the child in their tax household can apply.
How much is the CIM worth?
The amount depends on your adjusted taxable income:
| Adjusted taxable income | Single-parent tax credit |
|---|---|
| < €60,000 | €3,504 maximum per year |
| €60,000 to €105,000 | Degressive amount |
| > €105,000 | €750 per year |
How is the CIM calculated for middle incomes?
If your income is between €60,000 and €105,000, the CIM is calculated using this formula:
CIM = €3,504 − (adjusted taxable income − 60,000) × 0.0612
Calculation example
A single parent with a taxable income of €75,000:
CIM = 3,504 − (75,000 − 60,000) × 0.0612
CIM = 3,504 − 918 = €2,586
Note: the CIM does not depend on the number of children. Whether you have one, two or three children, the amount stays the same.
How do you claim the CIM on your tax return?
The CIM is not automatic, you need to explicitly request it on your tax return.
The steps:
- Enter your family situation (single parent)
- Declare your dependent children and their tax residence
- Provide supporting documents if requested by the ACD (birth certificate, custody agreement, divorce decree, etc.)
taxx.lu advantage
On taxx.lu, simply tick "Are you a single parent?" in the Children section and declare your dependent children. The CIM is calculated automatically and included in your return.
Impact of child maintenance payments
Certain child maintenance payments you receive may reduce the CIM amount if they exceed a certain threshold. The reduction can be up to 50% of the excess amount.
If you receive child maintenance, make sure to check its impact on your CIM.
Frequently asked questions
Does the CIM depend on the number of children?
No, it only depends on your adjusted taxable income.
Can I combine the CIM with other tax benefits?
Yes! The CIM can be combined with the child tax allowance, deductible childcare costs and other deductions.
What happens with shared custody?
Only the parent who includes the child in their tax household can claim the CIM. With shared custody, this is usually the parent who receives the full family allowance or who has the child's main residence.
Can the CIM exceed the tax owed?
Yes, that's one of its advantages. If the CIM is higher than your tax bill, the excess is refunded to you.
Conclusion
The single-parent tax credit is an important tax benefit for single parents in Luxembourg, worth up to €3,504 per year for lower incomes.
taxx.lu advantage
With taxx.lu, the CIM is automatically calculated based on your situation. File your return and claim all the tax credits you're entitled to.
