What a 100-amp to 200-amp panel upgrade actually costs

Heat pumps, EV chargers, and legal suites all collide at the same grey box. A 100-amp service that was fine for a 1970s bungalow with a gas furnace is often not fine once you add a 240-volt compressor and a car. The electrician's quote to swap the panel is the small number. The utility's quote to feed that panel is the one that blows the budget.

This is planning information, not electrical or insurance advice. In Ontario, hire a Licensed Electrical Contractor. They file the ESA notification, book the inspection, and coordinate the utility disconnect. Other provinces have equivalent licensing. A service upgrade is not a homeowner Saturday project.

Start with a load calculation, not a rule of thumb

Plenty of 100-amp panels still have room. Plenty do not. The difference is a calculation under the electrical code, not a contractor glancing at the breaker labels. If the person quoting a heat pump or a suite did not mention load, ask. Our AC calculator includes a $2,600 panel-upgrade toggle as a planning allowance for the electrical work on the house side. Treat that as the electrician's job, not as Hydro.

Two invoices, not one

The house-side job is the panel, the meter base if it is undersized, the mast and weatherhead on an overhead service, grounding, and moving the existing circuits across. Trade-reported 2026 ranges for a straightforward overhead upgrade in Ontario often land around $2,000 to $5,000 all-in, including ESA, when the mast and the conductors from the street can already carry 200 amps. A clean swap with the existing mast reused sits at the low end of that. A new mast, a new meter base, and a scheduled disconnect sit at the high end and take weeks, not a day.

The utility-side job is whatever the local distribution company has to change on its side of the meter: underground cable, a trench, a pedestal, sometimes a transformer. Homeowners in the GTA report that part alone at $15,000 to $20,000 when the street feed cannot support 200 amps. Alectra, Toronto Hydro, Hydro One, and Hydro Ottawa each run their own process. Toronto Hydro's published service-upgrade path is: they contact you within ten business days, then a design and a Job Quotation that can take up to sixty days after they have the information. You do not control that calendar.

What the electrician cannot skip

• ESA notification of work, and an inspection before the utility will reconnect
• A utility disconnect and reconnect. The house will be without power for part of a day, sometimes longer if the inspection misses
• A meter base rated for the new service, which a 100-amp base often is not
• Grounding and bonding that meets today's code, not the 1960s water-pipe ground
• Coordination if the panel sits in a finished rec room, or if asbestos or knob-and-tube is in the way

When you should budget the ugly number

Overhead, existing mast in good shape, load calculation says you need 200 amps: budget the $2,000 to $5,000 band and hold contingency for a meter base. Underground service, a 1950s bungalow, or a utility that already told a neighbour the pedestal is maxed: get the utility quotation before you order the heat pump. A kitchen that assumes a $4,000 panel and then meets a $18,000 Hydro invoice is how those projects stall over winter.

Fuse panels and Federal Pacific Stab-Lok boards are their own reason to upgrade, even if the amperage looks fine on paper. Insurers care about those the same way they care about knob-and-tube. The electrician can tell you what you have. A home inspector noting "100 amp, looks original" is not a load calculation.