Luxembourg tax return (Belgian cross-border worker)
Wages, withholding, expenses — the form 100 for Belgian cross-border workers, ready to copy
How does it work?
Answer the questions below, then copy-paste each box and amount from the recap onto impotsdirects.public.lu · MyGuichet.lu. Nothing is sent to any administration: you stay in control from start to finish.
What we’ll ask you
- Your family situation?
- How many dependent children do you have?
- Does more than 50% of your household's professional income come from Luxembourg?
- Annual gross remuneration for 2025 from your Luxembourg employer?
- Luxembourg income tax withheld at source for 2025?
- Social security contributions withheld in 2025 ("deductible social contributions" line on the certificate)?
- Tax credits already granted through payroll in 2025 (CIS…)?
- How many days did you work from home in Belgium in 2025?
Frequently asked questions
What documents do you need to prepare "Luxembourg tax return (Belgian cross-border worker)"?
Have on hand: Certificate of salary, tax withheld and tax credits (sent by your employer in early 2026); Certificate of salary, tax withheld and tax credits. Every question in the flow tells you exactly where to find the requested amount on these documents.
How long does it take to prepare?
The flow has up to 14 questions (often fewer depending on your situation) — allow 2 to 5 minutes if you have your documents handy.
Is "Luxembourg tax return (Belgian cross-border worker)" free on CtrlC-CtrlV?
The preview of the first field is free. The full recap (every box, one-click copy amounts, a tip for each field) is part of the paid procedures: from €4.90, one-time payment, no subscription.
Is my information sent to the administration?
No. CtrlC-CtrlV only prepares your recap: you copy each box yourself onto impotsdirects.public.lu · MyGuichet.lu. Nothing is sent to any administration, and your answers stay in your browser.
Go further
- Luxembourg cross-border worker tax class: how does it work?
- Gross remuneration or withholding calculation basis: which figure to declare?
- Social contributions and tax credit (CIS) on the Luxembourg certificate: are they deductible?
- Belgian cross-border worker in Luxembourg: the 34-day telework threshold
- Luxembourg form 100: who must file it, and how to fill it box by box