1
general::
Phrase(s): get on the phone
Go to on the telephone., Phrase(s): get on(to) the (tele)phone [and] get on(to) the (telephone) extension
to pick up a telephone receiver to talk to someone or make a telephone call. • I’ll get onto the extension and talk with Fred. • I’ll get on the phone and call Fran right away.
McGrawhill's American Idioms And Phrasal Verbs