“Service panel” and “distribution panel” get used interchangeably a lot, but they’re not quite the same thing. Here’s the actual difference, and when you’d want one versus the other.
What a Service Panel Is
Your service panel — also called the main panel or main breaker box — is where power from the utility enters your home. It houses the main disconnect breaker, which can shut off power to your entire home at once, and it’s where your home’s grounding system connects. Residential service panels are typically rated 100 to 400 amps depending on the home. This is the panel most people mean when they talk about a “panel upgrade.”
What a Distribution Panel Is
A distribution panel — more commonly called a subpanel — is a secondary panel fed from the main service panel, rather than directly from the utility. It doesn’t have its own main disconnect; it relies on the breaker feeding it from the main panel for that protection. Subpanels are typically used to extend power to a garage, workshop, addition, or detached structure, or to add capacity for a specific large load like an EV charger without upgrading the entire main service.
Key Differences
| Feature | Service Panel | Distribution Panel (Subpanel) |
|---|---|---|
| Power source | Directly from the utility | Fed from the service panel |
| Main disconnect | Yes | No — relies on its feeder breaker |
| Typical use | Whole-home power distribution | Extending power to a specific area or load |
| Grounding | Bonded neutral and ground | Neutral and ground kept separate |
Which One Do You Need?
If your main panel is undersized for your home’s current or planned electrical load — frequent breaker trips, no room for new circuits, or you’re adding major loads like a heat pump and EV charger at once — a service panel upgrade may be the right call. If your main panel has capacity to spare but you need to extend power to a garage, addition, or a specific new load, a subpanel is usually the more targeted, less disruptive option. A licensed electrician can do a load calculation to tell you which situation you’re actually in rather than guessing.
Why This Is Licensed Electrician Work
Both panel types involve working directly with your home’s main electrical system, and a subpanel done incorrectly — particularly around grounding and bonding — is a real safety hazard even though it seems like a smaller project than a full service upgrade. Both require a licensed electrician and permit with inspection in Washington.
Not Sure Which You Need?
Mauro Electric Inc. has installed and upgraded service panels and subpanels throughout Bothell and the greater Seattle area since 1998. Contact us for a load assessment, or call 360-653-5300.
