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# What proof or documentation is required for income from the European institution?

To validate your situation with the tax authorities, it is sufficient to provide a **certificate/attestation from your employer or the HR department** of the European institution.
This certificate should confirm:

* that you were indeed **employed by the European institution**;
* the **exact period** during which you held this position.

This allows the authorities to recognise your status as a European employee without including this income in your Luxembourg tax return.