For many reasons it is most likely that a repossessed aircraft will operate under a “Permit to Fly” – this can often be the case where maintenance is overdue, or a relocation flight is required, and the aircraft is not an on AOC (Aircraft Operation Certificate) such as the case might be when the company operating it has failed.
Regarding EASA registered aircraft, it is important to be aware of some of the requirements for aircraft flights as operations are split into 2 major categories: that of commercial and non-commercial.
Non-commercial operations are broken into NC Non-Commercial & SPO Special Operations