Personal taxation · Luxembourg
Belgian cross-border worker: Luxembourg tax and assimilation
For a Belgian resident, assimilation to resident taxpayers in Luxembourg can be examined in particular through the route where more than 50% of the household’s professional income is taxable in Luxembourg. This test does not replace the other access routes and does not show that an option will be advantageous.
Financial Services Luxembourg · Licensed accountant · Head of the firm: Mickaël LOC. Editorial update: .
Do not mix up the bases of the tests
The general 90% rule is assessed individually on the relevant worldwide income. The Belgian route refers to the household’s professional income. The route based on net foreign income below EUR 13,000 relies on yet another condition.
These criteria are not calculated only on the net salaries paid into your bank account. The nature of the income and the right to tax it must be established before the ratio.
Household information
- Luxembourg and Belgian certificates for the year.
- Each person’s professional income and any other income needed for the calculation.
- Family situation, ownership of assets and changes of residence.
- Working days outside Luxembourg and supporting documents from the employer.
Belgian and Luxembourg taxation
The Belgian tax return and formalities must be examined separately. The tax treaty, the category of income and residence determine the applicable mechanism; an exemption in one State does not always mean there is no reporting obligation.
Having a Luxembourg salary does not allow you to apply the private-sector rule to public-sector pay or pensions. This income requires its own reading of the tax treaty.
Fictitious example and decision
A household earns professional income in both countries. The Belgian test may be relevant even if a standard individual test is not met. The consequences of the option must then be compared using the same complete data.
The calculation of the rate, the benefits available and foreign income may work in opposite directions. We prepare the Luxembourg file according to the engagement; preparation of the Belgian return and local coordination must be confirmed.
The firm’s other tax engagements
Depending on your situation, the firm also handles tax, VAT and payroll, the regularisation of late tax filings and assistance during a tax audit. Fees are listed in the firm’s fee grid.
Official sources and scope
- ACD: assimilation to residents, article 157ter
- ACD: questions from non-resident taxpayers
- ACD: tax treaties in force
The rules apply to the year and profile concerned. Examples flagged as fictitious explain a method; they are not an individual validation. The documents and options of your file are covered by a separate engagement.