> ## 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).

# Why isn't my document recognised by Auto Scan?

The main reason is often that the document sent **is not a standard tax certificate**, as expected by the system. Auto Scan is designed to recognise certain specific types of document (e.g. tax certificates, salary certificates, insurance certificates, etc.).

Other possible reasons are :


1. **Quality of the document**
* The document is blurred, badly cropped or difficult to read
* It is a photo and not a real scan
* The file contains several badly structured pages


2. I**ncompatible format**
* The format is not PDF, JPG or PNG
* The file is too large, corrupted or incorrectly saved


3. **Elements not legible**
* Presence of handwriting or annotations
* Text hidden, crossed out or highlighted
* Presence of stamps or signatures covering the amounts