IPA: /ˌɪn.təˈrɒf.ɪs/
KK: /ˈɪntərˌɔfɪs/
Relating to communication or activities that occur between different offices within the same organization.
The manager sent an interoffice memo to all employees about the upcoming meeting.
Interoffice → It is formed from "inter-" (meaning between) and "office" (from Old French *office*, meaning a place of duty or service). The word "interoffice" refers to communication or activities that occur between different offices or departments within an organization.
Think of things happening 'between' ('inter-') different 'offices' — that's what interoffice means.
No commonly confused words.