Marriage and civil partnership: joint tax return

Civil partnership (PACS): its own request and conditions

For a partnership, check in particular its registration, its duration during the year and the common household under the applicable rules. Being partners at the time you fill in the return is not enough to assume that all of the annual conditions are met.

The joint request, signatures and deadline must be checked against the official procedure. The situation of a non-resident partner may require additional analysis.

Marriage: separate the regime from the options

Domestic law sets out the cases of joint taxation for married taxpayers and the conditions for mixed resident/non-resident couples. Individual options, with or without reallocation depending on the case, have their own rules.

A withholding rate applied on a tax withholding card does not by itself constitute the final choice of annual taxation method. A comparison requires consistent income and expense figures for both people.

What a comparison must keep identical

• Year, residence and periods of tax liability.
• Income of each person, including income relevant to the rate.
• Documented deductions and conditions specific to each method.
• Credits already granted and creditable payments, to understand the balance.

Fictitious example and documents

Two people have very different incomes. The splitting mechanism may affect the tax scale, but foreign income or deduction conditions may change the overall result. A rule based only on the gap between salaries would be insufficient.

Prepare the deeds or certificates of partnership, the requested evidence of household and residence, the certificates of both people and previous decisions.

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: taxation of married taxpayers
• ACD: tax classes of resident taxpayers
• ACD: tax circulars

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.

Your next step

• Change of family situation and tax in Luxembourg
• Non-resident tax assimilation in Luxembourg: conditions