The refund of VAT is granted even if a VAT taxable person issues an invoice by mistake and the recipient does not register it and does not exercise the right of deduction.
Instead, the same VAT taxable person can not issue a credit note.
Source: Italian Tax Administration – Letter ruling No. 762 of the 4 November 2021 (in Italian)
Contribution by Fausto Capello of Gianni & Origoni