No reminder letter from the Luxembourg tax office in December? Here's what that really means for you

No letter from the ACD? Your 2024 Luxembourg tax return is still due by December 31. Late filing can mean fines of up to €25,000.

You might have been expecting a letter from the Administration des Contributions Directes (ACD) this month. Nothing in your mailbox? It's not an oversight, and it's definitely not good news.

The Luxembourg deadline is still December 31, 2025

Whether you received a reminder or not, the deadline to file your 2024 Luxembourg tax return hasn't changed. No letter doesn't mean no obligations, and it certainly doesn't protect you from the consequences of missing the deadline.

What you're actually risking

Even without an official reminder, Luxembourg tax rules still apply:

If you miss the filing deadline, the tax office can impose:

• a late filing surcharge of up to 10% of the tax owed;
• and in serious cases, a fine of up to €25,000.

Two key points to remember

1. First, a tax return received after December 31, 2025 could mean permanently losing your potential tax refund. If you're entitled to a refund but don't file on time, you could simply lose it altogether.
2. Second, the deadline is strict: only the date the ACD receives your return counts. The postmark means nothing. In other words, sending your return on 31 December isn't enough, it has to arrive by that date.

Don't let the tax office benefit from your oversight. Losing a refund or paying a fine is money you could be spending elsewhere.

How to avoid last-minute stress

With taxx.lu, you can complete your Luxembourg tax return online, at your own pace, before the deadline.

• Quick and easy: an intuitive platform that guides you step by step, whether you're a resident or a cross-border worker.
• Tax optimisation: our system automatically analyses your situation to maximise your deductions and potential tax savings.
• Auto-Scan feature: upload your tax certificates via our mobile app, and your return is pre-filled automatically.

Need a helping hand from an expert?

Please note: in December, our packages with expert review sell out fast. Our team of experts is working at full capacity and slots are limited. If you want your return reviewed before the deadline, don't wait, they can be gone from one day to the next.

Start my tax return on taxx.lu →