Idaho Electrical Code & NEC Adoption
This guide covers everything you need to know about electrical code in Idaho, including the current NEC edition (2023), wire sizing requirements, GFCI rules, electrician licensing, permit costs, and city-specific regulations. Idaho scores 95/100 on WireRef's compliance scale, placing it in the strict tier for code enforcement and safety oversight.
How Idaho scores on electrical code compliance
WireRef rates each state's electrical code environment on a 0-100 scale based on four factors: NEC edition recency, licensing requirements, permit enforcement, and active state amendments. Idaho scores 95/100, rated Strict.
This score is for informational purposes only. A lower score does not mean electrical work in the state is unsafe - many local jurisdictions enforce strict standards independently of statewide policy.
Wire sizing requirements in Idaho
The core ampacity values in NEC Table 310.16 have been unchanged since NEC 2017. Whether your Idaho jurisdiction uses NEC 2017, 2020, 2023, or 2026, the wire sizing for residential circuits is identical. The table below covers the most common residential circuits:
| Circuit | Wire (Cu) | Breaker | Insulation |
|---|---|---|---|
| Kitchen 20A outlet Required for all kitchen receptacle circuits per NEC 210.11(C)(1) | 12 AWG | 20A | NM-B (Romex) |
| Bathroom 20A outlet Dedicated 20A circuit required per NEC 210.11(C)(3) | 12 AWG | 20A | NM-B (Romex) |
| General lighting 15A Standard for bedroom, living room, hallway lighting circuits | 14 AWG | 15A | NM-B (Romex) |
| Electric dryer 240V 10/3 NM-B for cable; 10 AWG THHN in conduit | 10 AWG | 30A | NM-B or THHN |
| Electric range 240V 6/3 NM-B for cable run; dedicated circuit required | 6 AWG | 50A | NM-B or THHN |
| EV charger (48A) 48A continuous load x 1.25 = 60A breaker minimum | 6 AWG | 60A | THHN in conduit |
| Central A/C (3-5 ton) Sized per unit nameplate MCA and MOCP values | 10-6 AWG | 30-50A | THHN |
| 200A dwelling service 2/0 copper or 4/0 aluminum per Table 310.15(B)(7) for dwelling services | 2/0 AWG | 200A | USE-2 or THHN |
For long wire runs in Idaho (over 50 feet), voltage drop becomes the limiting factor before ampacity. Use our voltage drop calculator to verify your wire size keeps voltage drop under 3% for branch circuits or 5% total (feeder + branch).
GFCI requirements in Idaho
Under NEC 2023 (enforced in Idaho), GFCI protection is required in all kitchens - including the refrigerator outlet - plus all basements (finished and unfinished), laundry areas, and any area with a sink used for food preparation. This is significantly broader than prior editions.
| Location | GFCI requirement |
|---|---|
| Kitchen | All kitchen receptacles require GFCI regardless of location, height, or distance from sink. This includes the refrigerator outlet, which was previously exempt if more than 6 feet from the sink. Section 210.8(A)(6). |
| Bathroom | All bathroom receptacles require GFCI. This has been consistent since NEC 1975. Section 210.8(A)(1). |
| Outdoor | All outdoor receptacles require GFCI, including those not readily accessible. Receptacles at grade level must have in-use covers. Section 210.8(A)(3). |
| Garage | All garage receptacles require GFCI. Ceiling-mounted receptacles for garage door openers are included. Section 210.8(A)(2). |
| Basement | All basement receptacles require GFCI - both finished and unfinished areas. Previously only unfinished basements required GFCI. Section 210.8(A)(5). |
| Laundry | Laundry area receptacles within 6 feet of a sink require GFCI. The washer receptacle itself requires GFCI if within 6 feet of the laundry sink. Section 210.8(A)(10). |
See detailed GFCI rules by room: Kitchen · Bathroom · Garage · Outdoor · Basement · Laundry · Bedroom · Pool & Spa
What changed when Idaho adopted NEC 2023
When Idaho moved from NEC 2020 to NEC 2023, several rules changed that affect residential electrical work. Here are the key differences:
| Change | What it means |
|---|---|
| GFCI Requirements Expansion | Before: Kitchen GFCI required only for countertop receptacles (6-ft rule from sink) Now: ALL kitchen receptacles must be GFCI protected, plus hardwired appliances per 210.8(D) |
| General Lighting Loads Table Renumbering | Before: Table 220.12: Office = 1.5 VA/sqft (multiply by 1.25 for continuous) Now: Table 220.42(A): Office = 2.0 VA/sqft (already includes 1.25) |
| Dwelling Lighting Load Location | Before: Table 220.12: Dwelling = 3 VA/sqft, garages excluded Now: 220.14(J): Dwelling = 3 VA/sqft, garages INCLUDED |
| Box Fill EGC Counting | Changed in 2020 (not 2023): First 4 EGCs count as 1 conductor, each additional = 0.25. Pre-2020: ALL EGCs counted as 1 regardless of quantity. |
| EV Charging Article 625 | 2023 added emergency shutoff requirements, EVSE-specific receptacle configurations, and 5mA GFCI threshold for EV charging. |
Electrician licensing & permits in Idaho
Idaho requires electricians to be licensed. The primary license is the Electrical License, administered by the Idaho Division of Building Safety - Electrical Bureau. Visit the Idaho Division of Building Safety - Electrical Bureau website for application requirements and fees. Homeowners are generally exempt from licensing requirements when performing electrical work on their own primary residence - but permits and inspections are still required.
Verify a license: Check whether an electrician is properly licensed in Idaho using the official license verification portal. Always verify before hiring.
Permits: Electrical permits are required for most new circuits, panel upgrades, and service changes. Homeowners may pull permits for their own primary residence in most jurisdictions.
Typical permit costs: Residential electrical permits in Idaho generally range from $40-$150 depending on the scope of work and jurisdiction.
Permit costs are approximate and vary by jurisdiction. Contact your local building department for exact fees. Costs shown are for residential electrical permits and may not reflect commercial rates.
Common electrical projects that require a permit in most Idaho jurisdictions:
- New circuits - adding any new branch circuit to the panel
- Panel upgrades - replacing or upsizing the main electrical panel
- Service changes - upgrading from 100A to 200A service
- EV charger installation - new 240V circuit for Level 2 charging
- Hot tub or pool wiring - Article 680 requirements apply
- Detached structure wiring - garage, shed, or ADU subpanel
Work that typically does not require a permit includes replacing switches, outlets, and light fixtures on existing circuits (no new wiring). However, rules vary - when in doubt, call your local Idaho building department before starting.
License types in Idaho
| License Type | Experience | Exam | Details |
|---|---|---|---|
| Electrical Apprentice | See requirements | No | N/A |
| Journeyman Electrician | 8,000 hours (~4 years) | Yes | N/A |
| Master Electrician | Journeyman + 1 year | Yes | Journeyman + 1 year |
| Electrical Contractor | Must employ Master or Journeyman + insurance | No | Must employ Master or Journeyman + insurance |
Continuing education in Idaho
Idaho does not require continuing education for electrician license renewal. Effective 2025, CE is no longer required for electrical license renewal in Idaho.
License reciprocity
Licensed in Idaho? Your license may transfer to these states:
Reciprocity requirements vary. Contact the destination state's licensing board for exact transfer requirements. Some states require additional exams or documentation. See our reciprocity explorer for details.
Homeowner exemption: Yes. Homeowners may perform electrical work on their own residence. Permit required.
Major cities: building departments & local codes
While Idaho's statewide code provides the baseline, individual cities may have additional requirements, different permit fees, or local amendments. Below are the building department contacts for Idaho's largest cities.
| City | Building Department | Notes |
|---|---|---|
| Boise | Planning & Development Services | Follows state NEC adoption |
| Idaho Falls | Building Department | Follows state NEC adoption |
City-specific information last verified Apr 2026. Contact the building department directly for current fees and requirements. WireRef is not affiliated with any municipal building department.
EV charger permit requirements in Idaho
Most jurisdictions in Idaho require an electrical permit for Level 2 EV charger installation. A Level 2 charger typically requires a dedicated 240V circuit with a 50A or 60A breaker and 6 AWG copper wire (for a 48A charger at continuous load).
| Spec | Requirement |
|---|---|
| Typical circuit | 240V, 50A or 60A breaker, 6 AWG copper THHN |
| Permit required | Yes, in most jurisdictions |
| Continuous load rule | 48A charger x 1.25 = 60A breaker (NEC 210.20) |
| GFCI/disconnect | Disconnect within sight of charger per NEC 625. GFCI protection per NEC 625.54 (outdoor) or manufacturer requirements |
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See our complete EV charger wiring guide for detailed installation requirements. For state incentives and rebates, check the DSIRE database for Idaho-specific programs.
Frequently asked questions: Idaho electrical code
What NEC edition does Idaho currently use?
Idaho currently enforces NEC 2023. It became effective on July 01, 2023. This determines the baseline electrical safety requirements for all new electrical work in the state. Local jurisdictions may adopt more recent editions or add amendments.
Do I need an electrician license to do electrical work in Idaho?
Yes - Idaho requires a Electrical License for professional electrical work through the Idaho Division of Building Safety - Electrical Bureau. However, homeowners are generally exempt when working on their own primary residence.
Do I need a permit for electrical work in Idaho?
Yes - most electrical work in Idaho requires a permit, including new circuits, panel upgrades, and service changes. Typical residential permit costs range from $40-$150. Homeowners can typically pull permits for their own residence.
How much does an electrical permit cost in Idaho?
Residential electrical permits in Idaho typically cost $40-$150 depending on the scope of work and specific jurisdiction. Costs vary significantly between cities - contact your local building department for exact fees.
What wire size do I need for a 20-amp kitchen circuit in Idaho?
12 AWG copper is required for all 20-amp circuits regardless of which NEC edition Idaho enforces - the ampacity tables in Table 310.16 have been unchanged since NEC 2017. Use 12/2 NM-B (Romex) for standard cable runs or 12 AWG THHN in conduit. See our kitchen wiring guide for complete requirements.
Does Idaho require GFCI in the kitchen?
Yes - under NEC 2023, all kitchen receptacles require GFCI protection, including the refrigerator outlet. This was expanded in NEC 2023 from the previous rule that only covered countertop outlets within 6 feet of the sink.
Do I need a permit for an EV charger in Idaho?
Yes - most Idaho jurisdictions require an electrical permit for Level 2 EV charger installation since it involves a new 240V circuit. The typical installation requires a 60A breaker with 6 AWG copper wire for a 48A charger. See our EV charger wiring guide for complete specs.
How do I verify an electrician's license in Idaho?
You can verify any electrician's license status through the official Idaho license verification portal. Always verify before hiring an electrician for your project. Ask for the license number upfront and confirm it is active and in good standing.
How does Idaho's electrical code compare to other states?
Idaho scores 95/100 (Strict) on WireRef's compliance scale. This places it among the strictest states, with a current NEC edition, mandatory licensing, and active permit enforcement.
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States are color-coded by NEC edition: 2023+ current, 2020 one cycle behind, older/local two+ cycles behind.
NEC 2023 references verified April 2026