Plan on a permit, an inspection, and a utility process. A 100-to-200-amp heavy-up changes service equipment, grounding, and usually the meter socket — work that building departments and utilities want to see. The licensed electrician typically pulls the electrical permit, schedules the rough or service inspection if one is required, coordinates the disconnect, and calls for a final inspection before or at reconnect. Some jurisdictions also want a separate utility company inspection or a meter-spot appointment. None of that is optional just because the work is in a single day.
What varies too much for a single number: permit fees, whether a building permit is required in addition to an electrical permit, whether the inspector and the utility come on the same day, and how long an unpassed inspection delays reconnect. Fixr’s 2025 panel-upgrade guide mentions permit costs in a wide band; this site will not treat that as a nationwide fee schedule.
Ask the contractor, in the quote, who pulls the permit, who calls the utility, and what happens if the inspection fails. A job done without a permit is hard to insurance and hard to sell. The calculator is supporting material for why the upgrade was requested, not a substitute for the permit documents.
This is not a permit calculation, a utility approval, or a substitute for a licensed electrician, HVAC contractor, or the authority having jurisdiction. Panel Headroom is an independent educational site. It is not a utility, a certification body, or a contractor. Electrical and generator work that is done incorrectly can cause fire, shock, or carbon monoxide poisoning. Use the adopted electrical code and manufacturer instructions; pull permits where required.