Rule reminder
'Se' is the standard conditional. 'Qualora' (formal/written) = 'in the event that', slightly more distant hypothetical. 'Ove' (legal/bureaucratic) = archaic form of 'se', highly formal. 'Nel caso in cui' = 'in case that', emphasises contingency. All of these require the congiuntivo or condizionale in B2+ formal Italian.
_____ il pagamento non venisse ricevuto entro 30 giorni, il contratto si intenderà rescisso. (legal document)