How do I get a fixed rate?

To do this, you need to submit a request using form 166.

We can complete Form 166 for you at a cost of €59. Please feel free to contact us via chat or at help@taxx.lu.

You should also include a copy of your last three payslips and, if necessary, any proof of other income.

For more information, please contact your relevant RTS Office. You can find your RTS Office by using our free simulator

Updated on: 26/02/2026