6 years ago, my partner and I entered a civil partnership and had our agreement drawn up by a notary. We had opted for an undivided property regime. For professional reasons, we'd now like to adopt a separate property regime. Should we contact the notary?

Yes. If you wish to modify your Civil union, you can draw up a new agreement between yourselves, or have it drawn up by a notary. However, as your initial agreement was drawn up by a notary, you must send him your amended agreement so that he can register it (art. 515-3, al. 6 C. civ).