Frontalier Guide: Working in Luxembourg from France, Belgium or Germany

As a frontalier — a cross-border worker commuting daily to Luxembourg — you face a unique tax and social security situation. Around 200,000 people make this commute each working day from France, Belgium and Germany.

Who is a Frontalier?

• French frontaliers (largest group, ~100,000)
• Belgian frontaliers (~50,000)
• German frontaliers (~45,000)
• Workers from other EU countries living in Luxembourg's border zones

Tax Treatment by Country

France-Luxembourg Treaty French residents working in Luxembourg pay income tax in Luxembourg. France applies a tax credit to avoid double taxation. The 2019 treaty revision requires frontaliers to file a French tax return declaring global income.

Belgium-Luxembourg Treaty Belgian frontaliers pay all income tax in Luxembourg. Belgium has full information exchange but does not re-tax Luxembourg income.

Germany-Luxembourg Treaty German residents working in Luxembourg pay Luxembourg income tax. Germany requires a Welteinkommenserklärung (global income declaration) annually.

The 25-Day Home Office Rule

Since 2023, frontaliers can work from home for up to 25 days per year without affecting their Luxembourg tax status. Days worked in a third country also count toward this limit.

Social Security

• CNS health (3.05%), pension (8%), dependency (1.4%)
• Your healthcare coverage is Luxembourg-based
• Pension entitlements accrue in Luxembourg (CNAP)

Commuting Deductions

Frontaliers can deduct actual commuting costs or the professional expenses flat rate (€540/year). For long commutes, actual costs often exceed the flat rate and should be documented.