Quick answer
An electrical receptacle is the device mounted in a wall, floor or box that a plug fits into, connecting a cord to the building’s branch circuit through contacts for the hot, neutral and, on three-slot types, ground wires.
Most people call it an outlet, though electricians say receptacle. The standard household version is a duplex receptacle: two sockets on one strap, rated 15 or 20 amps at 125 volts.
Quick facts
The key facts about Electrical Receptacle, with sources:
- 20-amp version
- NEMA 5-20R, with a T-shaped neutral slot 2
- Safety standard
- UL 498 (attachment plugs and receptacles) 1
- Terminal colors
- Brass = hot, silver/white = neutral, green = ground 2
- Push-in terminal limit
- 15 A circuits and 14 AWG solid copper only, unless listed otherwise (NEC 2023 406.3(D)) 3
- Monthly owner check
- Plugs should fit snugly and the face should stay cool 6
Key takeaways
- “Receptacle” is the code word for what most people call an outlet.
- A duplex receptacle has two sockets on one device; it is the standard US wall outlet.
- The slot shape tells you the rating: a T-shaped slot means a 20-amp receptacle.
- New receptacles in homes must be tamper-resistant under the NEC, with a few exceptions.
- A loose, warm or scorched receptacle is a fire warning; stop using it and call an electrician.
What a receptacle is, and why electricians say it
A receptacle is the device a plug goes into. In everyday speech, the whole thing is an “outlet.” In the National Electrical Code, an outlet is any point where power is taken from the wiring, and the receptacle is the device fitted at that point. Electricians use “receptacle” to be exact.
The common household version is a duplex receptacle, which has two sockets, called faces, on one metal strap. A typical model such as the Leviton 5320 is rated 15 amps at 125 volts, is NEMA configuration 5-15R and is listed to UL 498 1.
Each socket has a short slot, a long slot and a round hole. On a correctly wired outlet the short slot connects to the hot wire. The long slot, on the left, connects to the neutral wire. The round hole connects to the ground.
Duplex outlet = duplex receptacle
A “duplex outlet” is the same thing as a duplex receptacle: two sockets on one device. This page covers it as the most common receptacle type.
How a receptacle connects a plug to the circuit
Behind the face, metal contacts grip the plug’s blades. Those contacts lead to screw terminals on the sides, where the wires land.
A brass screw takes the hot wire, a silver screw takes the neutral and a green screw takes the ground 2.
Leviton’s 5320 accepts 14, 12 or 10 AWG copper on its side screws 1.
Many receptacles also have push-in holes on the back. The 2023 NEC limits push-in terminals to 15-amp circuits and 14 AWG solid copper unless the device is listed and marked for more 3. Our backstab wiring page explains why many electricians avoid them.
A tab joins the top and bottom sockets on each side. When that tab is broken off, the two sockets can be fed separately, for example so a wall switch controls one socket for a lamp.
- Brass screwsHot (ungrounded) wire
- Silver screwsNeutral (grounded) wire
- Green screwEquipment ground
- Connecting tabsJoin top and bottom sockets
- Mounting strapBonds to the box and holds the device
Source: [2]
Types of receptacles you will see in a home
| Type | What it does | Where it is used |
|---|---|---|
| Duplex 5-15R | Two 15 A, 125 V grounding sockets | Most rooms |
| Duplex 5-20R | 20 A, with a T-shaped neutral slot | Kitchens, laundry, garages |
| Tamper-resistant (TR) | Shutters block objects pushed into one slot | Required in dwelling units 4 |
| GFCI receptacle | Cuts power on a ground fault; TEST and RESET buttons | Kitchens, baths, outdoors, garages |
| AFCI receptacle | Detects arcing faults | Where AFCI protection is required |
| USB receptacle | Adds built-in USB charging ports | Kitchens, bedrooms, desks |
| 240 V receptacles | Different blade shapes for dryers and ranges | Laundry, kitchen, EV charging |
Reading the slot shape
| Configuration | Rating | How to spot it |
|---|---|---|
| NEMA 5-15R | 15 A, 125 V, grounding | Two straight slots and a round ground hole 1 |
| NEMA 5-20R | 20 A, 125 V, grounding | The neutral slot has a sideways T 2 |
| Two-slot (no ground hole) | Older, ungrounded | Common in homes wired before grounding was standard |
Example: reading a receptacle’s data sheet
Real specifications from two manufacturer data sheets show what the ratings mean for you.
| Spec | Leviton 5320 duplex 1 | Leviton T5835 USB receptacle 2 |
|---|---|---|
| Rating | 15 A, 125 V AC | 20 A, 125 V AC |
| NEMA | 5-15R | 5-20R |
| Tamper-resistant | Not stated on the spec page | Yes |
| Wire on screws | #14–#10 AWG copper | 14–12 AWG |
| Push-in terminals | #14 AWG solid copper only | Not listed (back and side wire) |
| Standards | UL 498, NEMA WD-6 | UL 498 and UL 1310 |
The rating tells an electrician which circuits the device may go on. A 15 A receptacle may be used on a 20 A circuit only where the code allows it; that is the electrician’s call.
Where receptacles are required
The NEC tells builders where receptacles must go, how far apart, and which ones need GFCI, AFCI or tamper-resistant protection. In the 2023 edition, 406.12 requires tamper-resistant receptacles in all dwelling units, plus garages, accessory buildings and common areas 4. Kitchens, bathrooms, outdoors, basements and garages carry GFCI rules.
The 2023 NEC also covers wallplates that add a night light or USB charger. Under 406.6(D), they must be listed, with the circuitry built into the plate 5. Leviton, a maker of such parts, recommends a USB receptacle instead of a plug-on plate 5.
What a good receptacle gives you
- A tight grip on the plug, which keeps contact resistance and heat low.
- A ground path for three-prong appliances, when the circuit has a ground.
- Built-in protection where needed: GFCI against shock, AFCI against arcing, TR shutters against children’s fingers and objects.
- Clear, coded slots that stop a 20 A plug going into a 15 A receptacle.
What a receptacle cannot do
A receptacle does not add capacity, since every socket on a circuit shares that circuit’s breaker. Plugging a heater and a microwave into the same duplex can trip the breaker.
A three-slot receptacle does not prove a ground: in older homes, three-slot devices were sometimes added to two-wire circuits. Only testing by an electrician shows whether the ground hole is connected.
What drives the cost of receptacle work
We do not publish prices here, because labor and device type drive cost: a GFCI, AFCI or USB receptacle costs more than a basic duplex; adding a new receptacle means running cable; older homes may need grounding work or box changes. See the electrical project cost tool for what drives the price in your area.
No source gives a fixed lifespan for a receptacle. Replace it when it no longer grips a plug, is cracked or discolored, or after any burning or arcing.
How an electrician replaces or adds a receptacle
Replacing or adding a receptacle is work for a licensed electrician. Some places let homeowners do minor work on their own home, but the safety rules on this site do not cover DIY wiring.
- The electrician confirms the circuit, its breaker size and whether it has a ground.
- They choose the right device: rating, TR, GFCI or AFCI as the code requires.
- They de-energize the circuit, verify it is dead with a tester, and make the connections.
- They test polarity, ground and any GFCI or AFCI function.
- Where a permit is needed, such as for new circuits, an inspector checks the work.
Our electrical repair service covers receptacle repairs and upgrades.
Owner checks for receptacles
The CPSC home safety checklist suggests checking outlets every six months 6. Safe checks you can do:
- Plugs should fit snugly, and CPSC says a loose fit means the outlet should be replaced 6.
- Faces and cover plates should be cool to the touch 6.
- Every cover plate should be in place, with no cracks.
- Press TEST and RESET on each GFCI receptacle monthly.
- Never break the ground pin off a three-prong plug 6.
Warning signs of a failing receptacle
Signs to act on: a plug that falls out, a warm or hot face, brown or black marks, a burning smell, crackling or sparks when you plug in, or a cracked body. Loose contacts raise resistance, and resistance makes heat.
Stop using it
If a receptacle is warm, scorched or sparks, unplug everything from it and turn off its breaker if you know which one. Do not open it; call an electrician instead. If there is smoke or flame, leave and call 911.
Standards and code rules
Receptacles are listed to UL 498 and built to NEMA WD-6 configurations; the Leviton 5320 data sheet lists both 1. Installation follows NFPA 70, the National Electrical Code, as adopted by your state or city.
Key 2023 NEC sections: 406.3(D) for terminals, including push-in limits and CO/ALR marking for aluminum wire 3; 406.6(D) for listed night light and USB wallplates 5; and 406.12 for tamper-resistant receptacles 4.
Insulated neutrals must be white or gray (200.6), and insulated equipment grounding conductors must be green or green with a yellow stripe (250.119) 7.
Receptacle compared with related terms
| Term | Meaning | Difference |
|---|---|---|
| Outlet | Any point where power is taken from wiring | A light fixture box is an outlet too; a receptacle is one kind of device at an outlet |
| GFCI | Shock protection device | Can be a receptacle, a breaker or portable |
| TR receptacle | Receptacle with shutters | A receptacle feature, required in homes |
| Branch circuit | The wiring from a breaker to its outlets | Feeds the receptacle and sets its limit |
| Dedicated circuit | A circuit serving one appliance | May end in a single receptacle |
Myths about outlets
- Myth Three holes means it is grounded.
- Reality Not always, because older circuits may have three-slot devices with no ground wire. Testing shows the truth.
- Myth Any receptacle works on any circuit.
- Reality Ratings matter, because a 20 A plug will not fit a 5-15R by design.
- Myth Push-in holes work with any wire.
- Reality Only 14 AWG solid copper on 15 A circuits, unless the device is listed for more 3.
- Myth Plug-in USB wallplates are the same as USB receptacles.
- Reality Listed USB wallplates have their own limits under NEC 406.6(D) 5.
State rules on who may replace a receptacle
Repair, replace or upgrade?
Use this guide to know what to ask for, and let an electrician decide the fix.
- If Plug falls out, no heat or marks
- Then Ask for a replacement receptacle
- If Warm, scorched or sparking
- Then Stop using it; call an electrician soon
- If Two-slot outlets throughout
- Then Ask about grounding or GFCI protection
- If Need charging at a desk or counter
- Then Consider a USB receptacle
Before you call
Note which outlets are affected and what was plugged in. Run the home electrical safety check to spot other issues for the same visit.
Questions about Electrical Receptacle
What is the difference between an outlet and a receptacle?
In everyday speech they mean the same thing, but in the electrical code an outlet is any point where power is taken from the wiring, including a light fixture box. A receptacle is the device you plug into, and electricians say receptacle to be precise.
What is a duplex receptacle?
It is the standard US wall outlet: two sockets on one device. Each socket has a hot slot, a neutral slot and, on modern types, a round ground hole. A typical duplex is rated 15 amps at 125 volts, NEMA 5-15R.
How do I tell a 15-amp from a 20-amp receptacle?
Look at the neutral slot, which is the longer one: on a 20-amp NEMA 5-20R receptacle, it has a sideways T shape. A 15-amp NEMA 5-15R has two straight slots, and the rating is also printed on the device.
Why do my plugs fall out of the outlet?
The contacts inside have worn and no longer grip the blades. CPSC’s home checklist says a plug that does not fit snugly means the outlet should be replaced. A loose contact can heat up, so do not ignore it.
Is a warm outlet dangerous?
It can be a warning sign. CPSC says outlets and switches should be cool to the touch; if not, stop using them until an electrician checks. Warmth can mean a loose connection, an overloaded circuit or a failing device.
Do I need tamper-resistant outlets?
For new and replacement work in homes, usually yes. The 2023 NEC requires tamper-resistant receptacles in all dwelling units, with exceptions such as receptacles more than 5½ feet above the floor or those that are part of an appliance.
Does a three-prong outlet mean my home is grounded?
No. Three-slot receptacles were sometimes installed on older two-wire circuits that have no ground. An electrician can test it, so never rely on the shape of the outlet alone.
What do the colored screws on an outlet mean?
Brass screws are for the hot wire, silver screws are for the neutral and the green screw is for the ground. The colors keep the plug’s narrow and wide blades on the right wires, which keeps lamp shells and switches on the right side.
How often should I check my outlets?
CPSC suggests a room-by-room electrical safety check every six months. Feel for warmth, check that plugs fit snugly, look for missing or cracked cover plates, and press TEST and RESET on GFCIs monthly.
Can I replace an outlet myself?
Rules on homeowner electrical work vary by state and city, and working on a live circuit can kill. This site does not give DIY wiring steps. A licensed electrician can replace receptacles, test grounding and add GFCI or AFCI protection where required.
Sources
- Leviton, 5320-WCP 15 Amp Duplex Receptacle product specifications, retrieved .
- Leviton, T5835-W 30W USB Type-C/C 20A Tamper-Resistant Receptacle specifications, retrieved .
- Leviton Captain Code (NEC 2023), Switches and Receptacles with Push-In Terminals & Wire Types (404.14(D), 406.3(D)), retrieved .
- Leviton Captain Code (NEC 2023), Tamper-Resistant (TR) Receptacle Requirements Expanded (406.12), retrieved .
- Leviton Captain Code (NEC 2023), Restrictions on Wallplates with USB or Nightlight (406.6(D)), retrieved .
- US CPSC, Home Electrical Safety Checklist (Pub 513), retrieved .
- EC&M, Code Q&A: NEC Requirements for Conductor Identification (2023), retrieved .
- Texas Department of Licensing and Regulation, 2023 National Electrical Code is almost here, retrieved .
- Washington State Register WSR 25-23-069 (L&I adopts the 2026 NEC), 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: Ratings, terminals and standards come from Leviton data sheets (5320-WCP, T5835-W). Code sections follow Leviton’s NEC 2023 guide (406.3(D), 406.6(D), 406.12) and EC&M on conductor colors. Owner checks follow CPSC Pub 513. No DIY wiring steps; no prices under G-COST.
Suggest a correction. We fix errors and say what changed.