How can a Belgian cross-boarder worker be assimilated to a resident taxpayer?

In order for a Belgian cross-border worker to be treated as a resident taxpayer, they must meet at least one of the following three conditions:

• At least 90% of their household income is earned in Luxembourg. Important: When calculating this percentage, the first 50 days worked abroad are counted as Luxembourg income.

Example: Thomas lives in Belgium and earns €70,000 in Luxembourg. He also receives €4,000 in interest in Belgium. Total income: €74,000. Part in Luxembourg: more than 94%. He exceeds the 90% threshold: he can be treated as equivalent.

• The household earns less than €13,000 net income abroad.

Example: Anna works in Luxembourg and earns €55,000. She earns €12,000 in rental income in Belgium. Her foreign income is less than €13,000. She can therefore be treated as equivalent, even if the Luxembourg part does not reach 90%.

• More than 50% of the household's professional income is earned in Luxembourg.

Example: Ben lives in Belgium. He earns €40,000 in Luxembourg and €30,000 in Belgium. Total professional income: €70,000. Luxembourg part: approximately 57%. He can be considered eligible as the 50% condition is met.

For married couples or couples living in a registered civil partnership (PACS), at least one of the partners must meet one of the three conditions.

Updated on: 23/02/2026