> ## 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).

# Is it possible to challenge a decision of non-assimilation?

If your income was not correctly taken into account by the tax authorities, you may challenge the decision by sending an appeal letter.
However, if your income was correctly taken into account by the tax authorities and you do not meet any of the conditions for assimilation, then challenging the decision is pointless.