There's no single right answer to how often an office needs cleaning. It depends on how many people use the space, whether clients visit, and what kind of work happens there.
Small offices with a handful of staff and few visitors usually do well with a weekly clean that covers desks, restrooms, the break area, floors, and trash, plus a quick mid-week tidy of the kitchen.
Busier offices, or any space where customers walk in, benefit from cleaning two to three times a week. Restrooms and entryways set a visitor's first impression and get dirty fastest.
Whatever the frequency, focus on high-touch points: door handles, light switches, shared keyboards, phones, and the coffee machine. These spread germs around a team faster than any other surface.
Finally, schedule cleaning around your hours. Early-morning or evening cleans mean your team never has to work around a vacuum, and they walk in to a fresh office every day the cleaners have been.