I would like to add one night to my booking.
'Aggiungere' — stress the second syllable: 'ag-GIUM-ge-re'. Double G before I makes a soft sound.
Use when calling the hotel to extend a booking you have already made. Do this as early as possible to ensure availability.
'Aggiungere' = to add. 'Una notte' = one night. 'Alla mia prenotazione' = 'to my booking'. 'Prenotazione' is the noun from 'prenotare'. This is a modification request, common in Italian hotel interactions.
Vorrei prolungare il mio soggiorno di due notti.
I would like to extend my stay by two nights.
'Prolungare' = to extend/prolong
È possibile restare fino a giovedì invece di mercoledì?
Is it possible to stay until Thursday instead of Wednesday?
States the change in departure day
C'è disponibilità per un'altra notte?
Is there availability for one more night?
Checks first before requesting the change
Italian hotels are generally flexible about extending stays when rooms are available. The same rate agreed at booking is usually honoured for the extra nights. However, during peak season (Ferragosto — around 15 August), rooms are scarce and extensions may not be possible.