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Late with your 2024 tax return? If filing was mandatory, you still need to submit it in January
Late with your 2024 Luxembourg tax return? If filing was mandatory, you still need to submit it. Find out how to sort out your situation with taxx.lu.
Missed the December 31 deadline for your 2024 Luxembourg tax return? Here's what you need to know.
Mandatory vs. voluntary filing: the key distinction
It all depends on your tax situation. The rules differ depending on whether you were required to file or not.
If your tax return was mandatory
You still have to file, even if it's late. The tax office (ACD) will process your return.
Your tax return is mandatory if you fall into one of these categories, for example:
- Married or PACS couples where both partners work in Luxembourg
- Annual taxable income exceeding €100,000
- Multiple sources of Luxembourg income (e.g. salary + unemployment benefits)
- Rental income or other income not subject to withholding tax
Watch out for penalties
Late filing can result in a tax surcharge of up to 10% of the tax owed, a penalty payment, and late interest of 0.6% per month. The longer you wait, the higher the bill.
If your tax return was voluntary
This is where it gets tricky. If you weren't required to file but were doing so to claim a refund, it's too late. The ACD will refuse to process your return, and you'll lose the refund you would have been entitled to.
Why the difference?
For voluntary returns, the 31 December deadline is a strict cut-off. After this date, the tax office considers that you've waived your right to a refund.
Why you shouldn't wait any longer
If you're required to file, every day counts. Here's why:
Late interest adds up. At 0.6% per month on the tax owed, the total can quickly become significant.
The ACD can assess you automatically. If you don't act, the tax office can estimate your income and set your tax bill itself, rarely in your favour.
You're blocking your deductions. Until your return is filed, you can't benefit from the deductions you're entitled to (commuting costs, mortgage interest, insurance, etc.).
How to file your late return with taxx.lu
Even after the deadline, taxx.lu is still here to help you sort out your situation. The platform works exactly the same way:
1. Create your account and let us guide you: our platform takes you through it step by step, with forms tailored to your situation (resident or cross-border worker, single or married, etc.).
2. Import your documents: use the Auto Scan feature to upload your salary certificates and other supporting documents. Part of your return is pre-filled automatically. Then review the imported data and complete the rest manually.
3. Have your return reviewed: with our Plus (€119) and Premium (€199) packages, a tax expert fully reviews your return before submission. The Premium package also includes a personalised video call to answer all your questions.
Expert review
When filing late, a professional review can help you avoid errors that would add to your penalties.
4. Generate your form: taxx.lu produces your Form 100 or 163, ready to send to the ACD by post or via MyGuichet.lu.
5. Optimise for next year: our system automatically analyses your data to identify potential deductions. These recommendations will help you maximise your tax outcome on your next return.
In summary
| Situation | Can you still file? | Consequences |
|---|---|---|
| Mandatory return | Yes, and you must | Possible penalties, but return will be processed |
| Voluntary return | Probably too late | Potential refund lost |
Don't let the situation get worse. If you were required to file, sort it out now, the sooner you submit, the lower your penalties will be.
Questions about your situation?
- Email: help@taxx.lu
- Live chat on taxx.lu
