Quick answer
An electrical meter base is the weatherproof enclosure and socket, usually on an outside wall, that holds the utility’s electric meter and connects the incoming service conductors to the conductors that feed your main disconnect.
The meter plugs into jaws inside the base, completing the circuit through the meter. In many service areas the homeowner owns the base while the utility owns and seals the meter.
Quick facts
The key facts about Electrical Meter Base, with sources:
- Holds
- The utility’s revenue meter, plugged into socket jaws
- Usual ownership
- Set by each utility; Snohomish County PUD makes the customer supply service entrance equipment and own townhome meter bases 1
- Point of connection (underground homes, example)
- At the meter base, per Snohomish County PUD 1
- Smart meters
- About 73% of U.S. residential meters were AMI (smart) in 2022 4
- Meter socket adapters
- Only utility-approved devices; PG&E limits them to single-meter homes up to 240 V / 200 A 2
Key takeaways
- The meter base is the box; the meter is the device that plugs into it.
- You usually own the base, while the utility owns, installs and seals the meter.
- A damaged or water-logged base is a fire risk and only the utility can safely pull the meter.
- Service upgrades usually replace the meter base too.
- Devices that plug in between the meter and base need utility approval.
What a meter base is
Find the outside wall where power enters your home. The round glass or plastic meter sits in a metal box. That box is the meter base, also called the meter socket.
Inside are heavy spring jaws. The meter’s blades push into the jaws, and current flows from the line side, through the meter, to the load side.
The line side connects to the utility’s supply: the service entrance conductors coming down from an overhead drop, or the lateral coming up from underground. The load side connects to the conductors that run to your main disconnect.
Most home meter bases are “self-contained.” All of the home’s current flows straight through the meter’s blades and jaws.
Larger services may use current transformers instead, so only a small sample current reaches the meter.
Either way, the base must be rated for the full service amperage, which is why a bigger service usually means a new base.
Utility service manuals spell out ownership. Snohomish County PUD, for example, says that for zero-lot-line townhomes all service wire and meter base installations are owned and maintained by the customer, and it puts the point of connection for underground residential service at the meter base 1.
How power passes through the meter base
- Utility service drop or lateral → line-side terminals of the meter base
- Line-side jaws → meter blades → meter measures kWh → load-side jaws
- Load-side terminals → conductors to the main service disconnect
- Main disconnect → panel → branch circuits
Types of meter bases
| Type | What it includes | Where used |
|---|---|---|
| Meter socket only | Socket and lugs, no breaker | Homes with an indoor main panel |
| Meter-main combination | Socket plus main breaker in one box | Common for upgrades; can serve as the outdoor disconnect |
| Meter with integral meter disconnect | Disconnect built into the meter mounting equipment | Can be the 2023 NEC emergency disconnect when marked 3 |
| Multi-gang meter stack | Several sockets in one assembly | Duplexes, apartments |
| CT-rated meter cabinet | Current transformers instead of direct-through jaws | Large services and commercial buildings |
Example: marking rules on a new meter-main
When service equipment is replaced, the 2023 NEC Section 230.85 rules apply. This example uses the marking text summarized by Larimer County 3.
| Device at the meter | Required marking | Note |
|---|---|---|
| Service disconnect (meter-main breaker) | EMERGENCY DISCONNECT, SERVICE DISCONNECT | Most common at homes |
| Meter disconnect not rated as service equipment | EMERGENCY DISCONNECT, METER DISCONNECT, NOT SERVICE EQUIPMENT | Installed per 230.82 |
| Other listed switch on the supply side | EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT | Ahead of the service disconnect |
| Label format | Red background, white text, letters at least ½ in high | On the outside front of the enclosure |
Scope, per Larimer: the rule covers new and replaced service equipment. A panel upgrade is the usual moment this comes up.
Where you meet the term
On a panel upgrade or service change quote, “new meter base” or “meter-main combo” is a line item. On a home inspection report, look for notes like “meter base corroded,” “meter base pulling from wall” or “missing seal.”
On your utility bill, the meter number identifies the meter, not the base. EIA counted about 119 million smart meters in 2022 4. A smart meter still plugs into an ordinary meter base.
Strengths and weak points
What it does well
- Lets the utility swap meters without rewiring.
- Clear boundary between utility metering and your wiring.
- A meter-main combo can serve as the marked outdoor emergency disconnect 3.
- Standard sizes make replacement routine.
Where it falls short
- Outdoor exposure means rust, water entry and loose jaws over time.
- Overheated jaws can burn the base and meter.
- Ahead of your main breaker, so faults inside it have no home-side protection.
- Replacing it requires the utility to pull the meter.
Limits
- Amp rating. A 100-amp base cannot serve a 200-amp upgrade.
- Utility-approved models. Many utilities publish approved socket lists.
- Add-on devices. PG&E allows only approved meter socket adapters, on single-meter homes up to 240 V and 200 A, with a Form 2S socket 2.
- Seals. The meter is sealed by the utility; breaking a seal is not the owner’s call.
What drives the cost of replacing one
No dollar figures here. See panel upgrade costs for service work pricing.
- Amp rating. 200-amp bases cost more than 100-amp ones.
- Meter-main vs socket only. A built-in breaker adds cost but may save a separate disconnect.
- Overhead vs underground. Conduit and trench work change labor.
- Damage. Burned or rotted wall sheathing behind the base adds repair.
- Utility coordination. Disconnect and reconnect scheduling and any fees.
- Lifespan. Rust and water exposure shorten life; inspections spot it.
How a meter base gets replaced
Licensed electrician work, coordinated with the utility.
- Electrician confirms the size and the utility’s approved base.
- Permit pulled; utility scheduled to pull the meter and disconnect.
- Utility removes the meter and cuts power.
- Electrician installs the new base, conductors and any meter-main, with required markings 3.
- Inspection; utility sets and seals the meter and restores power.
Upkeep
- Look at the base from a short distance a few times a year for rust, gaps or burn marks.
- Keep sprinklers, downspouts and plants away from it.
- Do not paint over labels or seals.
- Report a broken meter glass or missing seal to the utility.
Warning signs
Scorch marks, a melted or discolored meter, buzzing, a hot smell near the meter, water running into the box, or a base pulling away from the wall all need attention. Flickering lights across the house can also start at loose meter jaws.
Call the utility first for anything at the meter; they own it and can pull it. Then call an electrician for the base. If there is smoke or fire, call 911. Our emergency electrician page explains what to expect.
Never pull the meter
The meter base is live on the line side even with your main breaker off, and pulling a meter under load can cause an arc flash. Never remove the meter, break the seal or open the base. Only the utility removes meters.
Rules and standards
| Authority | Rule | What it covers |
|---|---|---|
| NFPA 70 (NEC), 2023 ed. | Section 230.85 | Outdoor emergency disconnect; meter disconnect option and markings 3 |
| NFPA 70 (NEC) | Article 230 | Service conductors and equipment at the meter 5 |
| Utility service manual | Varies by utility | Ownership, approved sockets, point of connection 1 |
| Utility tariff (example) | PG&E Electric Rule 31, effective Jan 16, 2026 | Customer-owned meter socket adapters 2 |
Meter base vs related equipment
| Equipment | What it is | Usual owner |
|---|---|---|
| Meter | Measures kWh; plugs into the base | Usually the utility |
| Meter base | Socket enclosure | Usually the customer; check your utility manual 1 |
| Main breaker | Service disconnect and protection | Customer |
| Meter socket adapter | Device between meter and base, e.g. some transfer switches | Customer, utility-approved only 2 |
| Utility transformer | Makes 120/240 V | Utility |
Myths
- Myth The utility owns the whole meter box.
- Reality The meter and the base are often owned by different parties. Snohomish County PUD, for one, puts townhome meter bases with the customer 1.
- Myth Turning off the main makes the base safe.
- Reality The line side stays energized.
- Myth Any plug-in meter adapter is fine.
- Reality Only utility-approved devices are allowed 2.
What differs by state and utility
Utilities set their own meter base rules and approved lists, and states adopt NEC editions on their own timelines. California’s PG&E, for instance, sets meter adapter rules in Electric Rule 31, with its current version effective January 16, 2026 2.
When it matters to you
Meter base condition matters during a service upgrade, after storm or water damage, when adding a generator or battery that uses a meter adapter, and when buying an older home. In each case, ask whether the base is rated, approved and in sound condition.
Check your service size with our step-by-step guide before you plan big new loads.
Who to call
Problem with the meter itself? Call the utility. Problem with the box, wiring or wall? Call a licensed electrician, who will coordinate with the utility.
Questions about Electrical Meter Base
What is the difference between a meter and a meter base?
The meter is the utility’s measuring device that records your kWh. The meter base is the socket box on your wall that the meter plugs into, connecting the utility supply to your home’s wiring. In many service areas the utility owns the meter and the homeowner owns the base; your utility’s service manual settles it.
Who is responsible for the meter base, the homeowner or the utility?
Often the homeowner, but the utility’s rules decide. Snohomish County PUD, for example, makes the customer supply the service entrance equipment and says townhome meter bases are owned and maintained by the customer, while the meter is sealed when installed. Check your own utility’s rules.
Can I replace my own meter base?
No. The base is energized on the line side even with your main off, and only the utility can pull the meter and cut power. Replacement is licensed electrician work with a permit, coordinated with the utility, which then sets and seals the meter after inspection.
What causes a meter base to burn?
Loose or worn socket jaws, corroded connections, water getting into the box, or loads beyond the base’s rating can overheat the connections. Heat then damages the jaws and meter further. Scorch marks, a melted meter or a hot smell are reasons to call the utility and an electrician right away.
Do I need a new meter base for a 200-amp upgrade?
Usually. A meter base is rated for a maximum current, and a 100-amp base cannot serve a 200-amp service. Electricians often install a meter-main combination during upgrades, which also gives the outdoor emergency disconnect that the 2023 NEC requires when service equipment is replaced.
What is a meter-main combo?
It is a single outdoor enclosure that holds the meter socket and the main service breaker. It lets first responders shut off power outside and can serve as the 2023 NEC emergency disconnect when marked “EMERGENCY DISCONNECT, SERVICE DISCONNECT.” The indoor panel then becomes a subpanel fed from it.
Can a transfer switch plug into my meter base?
Some meter-mounted transfer switches and adapters fit between the meter and the base, but only with utility approval. PG&E’s Electric Rule 31, for example, allows only devices on its approved list, on single-meter homes of 240 volts and 200 amps or less with a Form 2S socket.
Is a smart meter different from a regular meter base?
A smart meter is a different meter, not a different base. It plugs into the same kind of socket. EIA reported about 119 million smart meter installations in the U.S. in 2022, about 73% of residential meters. The utility handles any meter swap.
What should I do if my meter base is pulling away from the wall?
Call your utility and an electrician. A loose base can strain the service conductors and connections, letting water in or causing overheating. Do not push it back or try to fasten it. The electrician will repair the mounting and any damage once the utility makes it safe.
Sources
- Snohomish County PUD, Electric Service Requirements, Section 2: General Requirements, retrieved .
- PG&E, Electric Rule No. 31, Customer-Owned Meter Socket Adapter Devices (effective Jan 16, 2026), retrieved .
- Larimer County (CO), 2023 NEC Significant Code Changes, retrieved .
- U.S. EIA, FAQ: How many smart meters are installed in the United States?, retrieved .
- Mike Holt, NEC Requirements for Services, Part 1, EC&M (April 16, 2024), retrieved .
Expert review
Written by the HyreElectrical Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Checked against Snohomish County PUD’s service requirements, PG&E Electric Rule 31, Larimer County’s 2023 NEC summary, EIA’s smart meter FAQ and EC&M’s Article 230 summary on 2026-10-10.
Suggest a correction. We fix errors and say what changed.