The most notable difference between a qualified and an advanced electronic signature (as defined in eIDAS Regulation) becomes apparent in case of legal disputes or when a party contests the validity of an electronic signature.
The qualified level enjoys legal recognition and acceptance across all EU member states. It is the only one having the legal equivalent of a handwritten signature. This means that, in case of a dispute, the judge will view the qualified electronic signature in the same light as a handwritten signature. In addition, its validity is presumed and the reverse burden of proof principle is applied. So, the party contesting the signature will have to prove that the qualified e-signature is invalid.
If, on the other hand, the electronic signature is advanced, then the party who claims its validity will have to prove to the court that the advanced e-signature is indeed valid.