The taxable amount can be reduced in the case of cancellation, refusal or total or partial non-payment after the supply takes place under conditions which are determined by the Member States.
When a VAT taxable person starts the procedures for the judicial annulment of a contract, it can issue the credit note before the end of the judicial proceeding.
Source: Italian Tax Administration – Guidance No. 11 of the 6 August 2021 (in Italian)
Fausto Capello
Gianni & Origoni