> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://help.taxx.lu/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# 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 ](https://taxx.lu/simulation/bureau-imposition)