The most common complaint we hear from businesses switching janitorial providers isn't that the old crew was bad. It's that nobody knew what they were supposed to do. A written checklist fixes that, and it's the first thing to ask for when you're comparing quotes.
Every visit should cover the basics: trash and recycling emptied and relined, restrooms cleaned, sanitized, and restocked, break-room counters, sinks, and appliance fronts wiped, floors vacuumed or swept and mopped, and high-touch surfaces like door handles, light switches, and shared desks disinfected.
Weekly or monthly items get their own line: dusting vents, blinds, and high surfaces, cleaning interior glass and partitions, spot-cleaning walls and doors, detailing the refrigerator, and scrubbing restroom grout. When these are scheduled instead of 'as needed', they actually happen.
Finally, the checklist should name the frequency, the hours the crew will be on site, who to contact if something's missed, and how quickly it gets fixed. Ours says 24 hours. If a quote can't answer those four questions in writing, keep looking.