Why you shouldn't wait until January to file your Luxembourg tax return: 3 good reasons

Filing your tax return after 31 December can be costly. Here are 3 good reasons not to wait until January for your Luxembourg tax return.

In Luxembourg, filing a tax return is an important step for many taxpayers, whether it's required or done voluntarily to claim a refund. Yet so many people put it off until the end of the year, or even January.

Here's the thing: January is already too late. With an online solution like taxx.lu, you can get ahead of the game, work through your return at your own pace, and avoid any nasty surprises.

Here are three solid reasons not to leave it until the last minute.

1. Avoid fines, and don't lose out on a refund

Filing in January means missing the deadline. In Luxembourg, tax returns are generally due by 31 December of the following year (so your 2024 return needs to be in by 31/12/2025).

Wait until January, and you're taking two risks:

• A late filing penalty of up to €25,000 from the tax authorities (ACD)
• Losing any refund you were entitled to, simply because the return came in late

We're talking potentially hundreds or even thousands of euros gone, just because of a missed deadline.

Get it done before the year ends, and you stay on the right side of the rules, dodge the penalties, and keep your full refund intact.

2. Give yourself time to optimise for next year

Here's another reason not to wait: if you prepare your return earlier, you've still got time to do something about your tax situation for the current year.

You might consider setting up tax optimisation strategies that will count towards your next return, such as:

• A private pension plan (Article 111bis LIR)
• A home savings contract
• Deductible insurance policies, including:
  • life insurance
  • health insurance
  • home or car insurance
  • death cover
  • residual debt insurance

These all come with tax benefits, but the premiums usually need to be paid before 31 December to count.

With taxx.lu, you can:

• see exactly where you are for the current year
• spot the optimisation opportunities you still have (calculated automatically from your data)
• make decisions before the year ends—rather than kicking yourself in January for missing out

See all optimisation options

3. Cut the stress and get your paperwork sorted in time

Rushing to finish your return at the end of December, or worse, in January, puts you under serious pressure, both practically and mentally.

Leave it too late and you risk:

• Forgetting key documents:
  • tax certificates
  • loan interest statements
  • childcare receipts
  • insurance premium proofs
• Chasing banks, insurers, employers, and nurseries at the busiest time of year, when everyone else is doing the same thing
• Piling on stress during an already hectic period—holidays, year-end work deadlines, family commitments

Start earlier and you can:

• calmly list out what you need
• request documents without panic
• double-check the figures
• ask questions if anything's unclear

With taxx.lu, you can also:

• upload your documents easily and let the system pre-fill your data
• come back to your return over several sessions
• (depending on your package) have a tax expert review everything before you submit

The result? A more complete, more accurate return—and a lot less stress.

So when should you start?

Ideally:

• start gathering documents as soon as your first certificates arrive (usually between February and April for the previous year)
• plan to enter your return sometime during the year
• wrap everything up before the December rush

With taxx.lu, you can create an account, follow the step-by-step process, save your progress, and pick up where you left off. That gives you breathing room—if something's missing, or you have a question, you've got time to sort it out without the panic.

The bottom line

Don't leave your tax return until January!

By getting ahead, you:

• avoid late penalties
• don't miss out on refunds
• give yourself room to optimise
• spare yourself the stress

And with taxx.lu, you can do it all in a clear, structured, secure way—with expert help available if you need it.