Telework TrackerThe number you see everywhere — 34 days — is not a marketing line. It is the tolerance threshold often cited for days worked outside Luxembourg by a Belgian cross-border worker, under the tax rules that apply to that situation.
This article explains the general idea, not your personal case. It is not tax advice. For a concrete situation, a professional (employer, adviser, tax office) remains the reference.
Why 34 days matter so much
Below the threshold, the usual frame for many Belgian cross-border workers stays centred on Luxembourg taxation of employment income. Beyond it, the logic changes: days worked outside Luxembourg can trigger taxation in the country of residence — and not only on the “excess”.
In other words: the risk is not just “one day too many”. It is the regime tipping once the threshold is crossed.
What the threshold alone does not settle
- Proration — part-time work, mid-year start: your personal ceiling is not always a raw 34 calendar days.
- Day type — telework, business travel, leave: not everything counts the same way.
- Proof — the day someone asks for a history, a rough spreadsheet rarely holds up.
What to track in practice
- Your personal threshold (not only the generic 34).
- Every day outside Luxembourg that may count.
- An alert before you are at the edge — not after.
- An exportable history if employer or tax office asks.
In practice. Telework Tracker is built for that tracking: annual ring, alerts, calendar, and a PDF report on Pro. It does not replace a tax adviser — it helps you avoid discovering a breach too late.
Takeaway
The 34-day threshold is a warning light, not a formality. If you telework from Belgium while employed in Luxembourg, precise counting is not optional — it is how you stay in control of the risk.