Frontaliers mariés :


You have already received your letter RTS by mail from the tax administration.


Replying to this letter is very  important in order to let Luxembourg tax administration calculate your monthly withholding tax on your wage (rate RTS or « Retenue sur Traitements et Salaires »). The tax authorities will issue your 2018 income tax card with the right percentage monthly tax withholding.

Thanks to this percentage, the amount of monthly tax restraints can be calculated and deducted from your payslip of January, 2018 and following ones.


See on this matter: « Married crossborder workers : what to respond if you received one of 150,000 tax withholding mails sent by the tax administration ? »

In this letter, the date of October 31st is mentioned as deadline for replying.

Last week, the ALEBA, the labor union of banks and insurance companies has even requested to delay  this deadline by one month untill November 30th, 2017.

Actually, the date of October 31st was chosen only for practical reasons by the tax administration.


In every case will the tax administration handle your letter even if received after October 31st, 2017.

In case of late reception of your mail, the tax administration could not guarantee that your tax card will be issued on time in January, 2018 with the right monthly withholding tax rate percentage. In that case, you could receive a first tax card in tax class 1 followed a few time later by a second income tax card with the right withholding tax rate percentage.


Thus this date is not compulsory unlike that of March 31st of the year which follows tax year for the choice of the way of taxation : collective, pure individual or individual with reallocation. In other words, modifying your way of taxation from previous tax year after that date is not possible anymore.


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