Personal taxation · Luxembourg
Change of family situation and tax in Luxembourg
A family change can affect withholding tax, the method of taxation, dependent children and supporting documents. Steps for the current year must be distinguished from the annual treatment. Updating the tax withholding card does not automatically settle all the tax consequences.
Financial Services Luxembourg · Licensed accountant · Head of the firm: Mickaël LOC. Editorial update: .
One event, several checks
| Event | Tax questions | Useful documents |
|---|---|---|
| Marriage | Taxation and any options for the couple | Certificate, residence and each partner's income |
| Partnership | Conditions and request for taxation | Registration, duration and household |
| Separation or divorce | Date, applicable regime, children and maintenance payments | Decision, agreement and payments |
| Death | Persons, periods and signatures required | Certificate, income and file documents |
Do not confuse the withholding card with the tax return
The tax withholding card is used to calculate deductions during the year. Form 100 or the applicable annual tax adjustment covers the full year. A change known to the register may trigger an update, but some requests still have to be made.
Check the validity date of the documents and keep earlier versions. The situation on the day you file is not always the one that determines the treatment of the whole year concerned.
Children and maintenance: reconcile the data
The child's attachment to a household, family allowances, residence and any maintenance payments may affect different regimes. Shared custody does not automatically allow every benefit to be granted in full to each parent.
Fictitious example: a separation occurs in the middle of the year and childcare costs are shared. You need to establish who bears the costs and which entitlements apply, without deducting the same expense twice.
Preparing the review
Draw up a timeline and gather the certificates, decisions and income of the persons concerned. Where two countries are involved, check recognition of the status and the relevant tax treaties.
After a death, inheritance matters and income tax are separate issues. The signatory, the procedures and the engagement must be identified with the competent professionals.
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: tax classes of resident taxpayers
- ACD: taxation of married taxpayers
- ACD: deductions and Forms 100, 163, 164
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.