Skip to content
CrossBeamStart a pre-check

Building Code Reference

Got a CEC 406.12 correction?

Tamper-resistant receptacles

For builders in California, Greater Seattle, the Las Vegas area, the Denver area and Kansas City · CrossBeam Permits

What this code requires, how to fix it, and how cities and counties review it

What this code requires

CEC 406.12 requires that all 125-volt, 15- and 20-ampere receptacles installed in dwelling units be listed tamper-resistant receptacles. These outlets have internal shutters that only open when equal, simultaneous pressure is applied to both slots — which a plug does but a stray key, wire, or paperclip does not. The requirement covers nearly every outlet in a home: living rooms, bedrooms, hallways, kitchens, bathrooms, garages, and outdoor locations. Single-family homes, ADUs, condos, and apartment units all fall under this rule in California.

How to fix it

  1. Confirm TR designation in your electrical schedule

    Go to your electrical fixture schedule or legend and find the receptacle entries. Every 125- or 250-volt, 15A or 20A nonlocking receptacle in the dwelling unit needs a note or symbol that says "TR" or "tamper-resistant" — not just the amperage and voltage. If your schedule says "20A/125V duplex" without "TR," that is the correction. Add "TR listed per CEC 406.12" to the description field for every applicable outlet type in the schedule.

  2. Identify which receptacles are exempt

    Not every outlet in the building needs to be TR-listed. Exempt locations include: receptacles that are not accessible (e.g., behind a refrigerator or built-in appliance), receptacles mounted more than 5.5 feet above the finished floor, receptacles that are part of a luminaire or appliance assembly, and single receptacles or duplex receptacles used for appliances in dedicated locations that are not easily moved. Mark these exemptions clearly on the plans with a note explaining why each is exempt — otherwise the plan-checker will flag them anyway.

  3. Address GFCI and TR combination outlets separately

    Locations that require GFCI protection — bathrooms, kitchens, areas within 6 feet of a sink, garages, outdoors, crawl spaces, and basements — also need TR listing. You cannot use a standard GFCI outlet and assume TR is included. Look for devices marked "GFCI/TR" (both listings on the same device) or use a GFCI circuit breaker combined with TR outlets at each location. Call this out in your electrical notes: "GFCI/TR duplex receptacle per CEC 210.8 and CEC 406.12."

  4. Mark AFCI-required circuits with TR outlets

    Bedrooms and most living areas in new construction also require AFCI protection per CEC 210.12. The AFCI requirement is on the breaker, not the outlet, but make sure your plans distinguish between the breaker type and the outlet type. The outlet still needs to be TR-listed. Show "AFCI breaker + TR outlet" in your panel schedule and on the floor plan notes so the two corrections do not come back as one bundled comment.

  5. Add a TR general note to the floor plan sheet

    Add a general electrical note on the floor plan sheet (not just the schedule) that reads: "All 125- and 250-volt, 15- and 20-ampere nonlocking receptacles in the dwelling unit shall be listed tamper-resistant per CEC 406.12." Even if your schedule is correct, a general note makes it impossible for the plan-checker to miss. Keep it short and cite the code section directly. This saves you from a follow-up comment asking where on the plans the TR requirement is addressed.

  6. Verify that replacement receptacles get upgraded

    If you are doing a remodel and replacing any existing receptacles, those must also be upgraded to TR. It does not matter that the original outlet was installed before TR was required — the act of replacing it triggers the current code. Note on the plans: "All replaced receptacles to be TR-listed per CEC 406.12." If you are not replacing existing outlets, you do not need to upgrade them, but if you are on the fence, the TR devices cost about the same as standard ones and avoid a re-inspection argument.

  7. Check outdoor and garage locations for all required listings

    Outdoor receptacles and garage outlets carry the most code layers: GFCI per CEC 210.8, weatherproof in-use covers per CEC 406.9, and TR per CEC 406.12. Your plans need to show all three on each outlet symbol or in the electrical note for those locations. Use a composite callout: "Outdoor: GFCI/TR receptacle, weatherproof in-use cover, 20A circuit." Plan-checkers working through a corrections checklist will mark each missing requirement separately, so call them all out in one place.

  8. Resubmit with revision clouds highlighting every change

    When you resubmit, cloud every sheet you changed and add a revision bubble. On the electrical sheet, circle the updated schedule entry and the new general note. In your response-to-corrections letter, write: "CEC 406.12: TR designation added to all applicable receptacles in the electrical schedule; general note added to sheet E-1." This closes the loop for the plan-checker and avoids a third-round comment asking where the change was made.

Take the CEC 406.12 fix steps with you

All 8 steps in one email, so you have them on site instead of on this page.

Why you got flagged

Plan-checkers flag CEC 406.12 most often because the electrical notes on the plans never call out tamper-resistant receptacles by name. It is easy to just write "20A/120V duplex receptacle, qty per plan" in the electrical schedule without specifying the TR listing, and that is exactly what the plan-checker is looking for. The CEC requires TR receptacles at essentially every outlet in a dwelling unit, so a generic note without the TR designation is a guaranteed correction.

The second common flag happens on additions and ADUs where the plans specify standard receptacles and the contractor argues that only new areas need the upgrade. That is wrong. CEC 406.12 applies to all 125-volt, 15- and 20-amp receptacles in the dwelling unit, including existing ones that are replaced. If you are pulling a permit that involves replacing or adding any outlet, it needs to be TR-listed.

Bathroom and kitchen remodels get hit on this regularly. A bathroom remodel will already draw a GFCI correction, and then a separate TR correction because the plans show GFCI receptacles without confirming they are also TR-listed. GFCI and TR are independent listings; you need outlets that carry both (look for "GFCI/TR" markings on the device). Specifying only "GFCI" in the notes leaves the TR piece unaddressed.

Garages and outdoor areas trip contractors up because those locations have so many other requirements (GFCI, weatherproof covers, AFCI in some cases) that TR gets overlooked. List every requirement explicitly in your electrical notes. Do not assume the plan-checker will infer that TR is understood.

The official code

California Building Standards Code, Title 24, Part 3 — California Electrical Code (CEC 406.12 Tamper-Resistant Receptacles)

Read the source →

Common questions

Do tamper-resistant receptacles apply to ADUs?
Yes. An ADU is a dwelling unit under the CEC, and CEC 406.12 applies to all dwelling units in California. Whether it is a detached ADU, a garage conversion, or a junior ADU carved out of the main house, every 125-volt, 15- and 20-amp outlet in that unit needs to be TR-listed. The plan-checker will review the ADU electrical sheets as a separate dwelling and flag any outlets that do not show the TR designation.
Is a tamper-resistant receptacle the same as a GFCI receptacle?
No. These are two separate listings, and a location can require both. GFCI (ground-fault circuit interrupter) protection prevents shock from current leaks and is required in wet locations like bathrooms and kitchens. TR (tamper-resistant) shutters prevent objects from being poked into the slots and are required at every dwelling-unit outlet regardless of location. Where both apply (bathrooms, garages, outdoors), you need a device listed as both "GFCI" and "TR," typically marked "GFCI/TR" on the face. Do not assume a GFCI outlet is automatically TR-listed.
Do I need to replace existing receptacles that are not tamper-resistant?
Not unless you are already replacing that outlet as part of your permitted work. If the existing outlet is staying in place and untouched, CEC 406.12 does not require you to pull it. But if you are replacing it, even as a like-for-like swap, the new device must be TR-listed. The trigger is the act of replacement, not the age of the original. When in doubt, check with your inspector before opening the wall, since some local offices apply a broader disturbance test.
Which locations are exempt from CEC 406.12?
The CEC lists several exemptions: receptacles mounted more than 5.5 feet above the finished floor, receptacles that are not readily accessible (built-in behind fixed appliances like a refrigerator), receptacles that are part of a luminaire or appliance, and dedicated single or duplex receptacles for specific non-portable appliances. If you are citing an exemption on your plans, label each exempt outlet with a note: "receptacle above 5.5 ft AFF, exempt per CEC 406.12 exception." An unlabeled outlet without TR designation will come back as a correction every time.
Does CEC 406.12 apply to commercial buildings?
No, CEC 406.12 targets dwelling units specifically. It covers single-family homes, duplexes, condos, apartment units, townhomes, ADUs, and live-work units with a residential component. A pure commercial space such as an office, retail store, or restaurant is not a dwelling unit and the TR requirement does not apply there. Mixed-use buildings need TR in the residential portions only. If you are unsure how the jurisdiction classifies a particular space, check the occupancy designation on the approved plans.
Can I use a standard outlet with a child-proof cover plate to satisfy CEC 406.12?
No. A cover plate is not a listed device and does not satisfy CEC 406.12. The tamper-resistant function must be built into the receptacle body itself. The internal shutters have to be part of the outlet, not a clip-on accessory. Inspectors check the outlet face for the "TR" marking that manufacturers stamp on listed devices. If it is not there, it fails the inspection regardless of what is covering the slots.
Are USB combo outlets required to be tamper-resistant under CEC 406.12?
If the USB combo outlet includes standard 15A or 20A, 125-volt receptacle slots (NEMA 5-15 or 5-20), those slots must be TR-listed. Many USB combo outlets are sold with TR-listed receptacle faces, but verify the product listing before specifying them. If the USB combo has only USB-A or USB-C ports and no standard NEMA slots, the TR requirement does not apply to those ports since they are a different form factor. Specify by model number in your electrical schedule if you are using combo devices to make it easy for the inspector to verify the listing.

Related corrections

Check my plans for this →