Married cross-border commuters :


You have already received your RTS letter by post from the tax authorities.


Responding to this letter is very important in order to allow the Luxembourg tax authorities to calculate your monthly withholding tax on your salary (RTS rate or “Reduction on Salaries and Salaries”). The tax authorities will issue you your 2018 income tax card with the correct monthly tax deduction percentage.


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


See on this subject: “Married cross-border workers: what to answer if you receive one of the 150,000 withholding tax letters sent by the tax authorities?” »

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

Last week, ALEBA, the banking and insurance union even asked to postpone this deadline by one month until November 30, 2017.


In reality, the date of October 31 was only chosen for practical reasons by the tax authorities.


In any case, the tax authorities will process your mail even if it is received after October 31, 2017.

In case of late receipt of your mail, the tax authorities cannot guarantee that your tax card will be issued on time in January 2018 with the correct percentage of monthly withholding tax. In this case, you could receive a first tax card in tax class 1 followed some time later by a second income tax card with the correct withholding rate percentage.


Thus this date is not mandatory, unlike that of March 31 of the year following the tax year for the choice of the method of taxation: collective, pure individual or individual with reassignment. In other words, it is no longer possible to modify your method of taxation for the previous taxation year after this date.


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