Goodbye. Have a good day.
Stress 'ar-ri-ve-DER-la'. 'Giornata' = jor-NA-ta.
Use this formal phone farewell when ending a professional call. 'Arrivederla' (formal) is more appropriate than 'arrivederci' for business calls with strangers.
'Arrivederla' = goodbye (formal, literally 'until I see you again — using 'la'). 'Arrivederci' = goodbye (informal/general). 'Buona giornata' = have a good day. Italian farewells match the time of day: 'buona giornata' (morning/daytime), 'buona serata' (evening), 'buona notte' (night — usually in person).
Buona serata, arrivederci.
Good evening, goodbye.
Evening farewell.
A presto. Ciao!
See you soon. Bye!
Informal ending.
Grazie per la sua disponibilità. Arrivederla.
Thank you for your assistance. Goodbye.
Formal, appreciative closing.
Italian formal phone farewells are longer and more elaborate than in Anglo-Saxon cultures. A sequence of 'grazie a lei, prego, arrivederla, buona giornata, grazie, arrivederla' before actually hanging up is perfectly normal and expected in professional Italian contexts. Abrupt farewells are considered impolite.