What is the tax assimilation of non-resident taxpayers to resident taxpayers?

Assimilation is a Luxembourg tax regime that allows certain non-residents to be taxed as residents, in order to benefit from the same tax advantages (deductions, allowances, tax classes).

An assimilated non-resident:

• is taxed on all of their income, like a resident;
• can benefit from tax deductions (loan interest, insurance premiums, special expenses, etc.);
• may have access to a more favorable tax class, notably tax class 2 for married couples.

Main conditions

Assimilation is possible if one of the following conditions is met:

• at least 90% of worldwide income of one of the taxpayers is taxable in Luxembourg;
• for Belgian residents, more than 50% of the household’s professional income is taxable in Luxembourg;
• annual net income not taxable in Luxembourg is below €13,000.

In all cases, foreign income must be declared, even if it is not taxed in Luxembourg.

Purpose

• To reduce taxes for cross-border workers (France, Belgium, Germany) whose main income comes from Luxembourg.
• To grant access to the same tax benefits as Luxembourg residents.

Updated on: 21/01/2026