My contractor recently added a 20-Amp circuit to my kitchen while he was remodeling it. He explained that the circuit was 20-Amp, and the non-GFCI outlets he installed all have the little horizontal line on the side, which I always thought was the designator for a 20-Amp outlet and 20-Amp circuit. That is, I thought that the “little extra line” is used to plug in a 20-Amp device which has a different plug configuration from a 15-Amp.

And I even found answers here and here that confirm what I always thought: if it has the line it is 20-Amp, and if it doesn’t it is 15-Amp.

But I noticed my contractor installed a couple of GFCIs that don’t have the extra line on the side of the plug. I mentioned this to him, and he explained that the GFCI outlets he installed really were 20-Amp outlets, they just don’t have that extra line.

I thought he was trying to save a few bucks by installing a 15-Amp outlet and assumed I wouldn’t know or notice, but he quickly reassured me by pulling off the plate cover and showing me the side of the outlet where it was stamped in the plastic “20 Amp.” So now I’m confused. What does the little line on the outlet mean? Is there a difference between a 20 Amp outlet with or without the extra line?

BTW, in trying to research this question before posting, I discovered that even if he had installed 15-Amp outlets on a 20-Amp circuit, it would have still been code, as answered by these questions:

I live in the USA, for purposes of wiring codes and outlet types related to this question.


I took apart the outlet again and see both the 20 Amp the contractor pointed out originally, plus a 15 Amp on the other side. I agree with the answer that this is a 15 Amp receptacle with a 20 Amp pass through.

3 Answers 3


A receptacle without that horizontal slot is only rated to supply 15 amps to a device that's plugged into it. GFCIs are no exception to this. That "20 Amps" stamp is likely stating the receptacle's pass-through rating, or the amount of current it can supply to sockets downstream of it.

There are GFCI devices with that horizontal slot available, which will supply 20 amps to attached devices, and can be found online with a quick Google for "20 amp GFCI receptacle".

You cannot plug a 20 amp device directly into any receptacle without that horizontal bar, be it a regular receptacle, or a GFCI.

  • This is correct the outlet may be stamped 20 for pass through and will work fine (I don't remember seeing any 20 amp rated kitchen appliances) one with a horizontal and a verticle blade.
    – Ed Beal
    Jun 18, 2017 at 15:25

Underwriter's Laboratories requires that all 15A (on their face) receptacles have, internally, circuit paths which are rated for 20A.

That dances together with the Electrical Code, which allows 15A receptacles plural to be used on 20A circuits, as is the case you will often find in kitchens and bathrooms.

By making GFCIs 20A internally but 15A on their face, it allows you to use the same GFCI on both 15A and 20A circuits. If the receptacle had the T-neutral, that would mean it could not be used on 15A circuits.


NEC 210.24 allows you to put a 15A receptacle on a 20A circuit if it has 2 or more outlets on a circuit. The thinking behind it is the use of the receptacle. Is it being used for devices that are rated at 12A or less, or is it being used for a specific purpose that requires a 20A circuit? So it is rating and approving the demand of the device instead of the demand of the circuit.

Any device that requires a 20A load will have a cord connecter with the 6-20R configuration. That means it won't be able to plug into any 15A device.

The standard 15A receptacle is a NEMA 6-15R and the 20A receptacle is a NEMA 6-20R.

Hope this helps.

  • That's the critical point--an outlet can be rated for 20A and used on a 15-amp circuit, but a keyed 20A outlet must be used on a 20A circuit, which protects the device having the keyed plug.
    – isherwood
    Jun 16, 2017 at 17:47
  • You mean NEMA 5 not 6. Jun 16, 2017 at 18:10
  • 1
    @Retired Master Electrician I do appreciate your comment, but it does not actually answer my question. My original question already linked to three separate questions and answers here on this site that stated 15A receptacle on 20A circuit is code. My question is, "what is the difference between a 20 Amp receptacle with the line and a 20 Amp receptacle without the extra line in the plug connector?" Maybe to phrase it another way, is there such thing as a 20A receptacle without the extra line in the plug connector?
    – jozolo
    Jun 16, 2017 at 20:49
  • Not an electrician, so take this with a grain of salt, but I have never seen a 20a receptacle without the extra slot that you'd expect. There is such a thing, however, as a 15a receptacle (normal slots) with 20a passthrough (aka, feed through). For instance, this image: homedepot.com/catalog/productImages/1000/d8/… Jun 17, 2017 at 16:27
  • @jozolo - I suppose I wasn't that clear. In answer to your question - no. The NEMA configurations define the receptacle and outlet configuration for the proper amperage usage of the equipment or device. I also stand corrected by Harper. Jun 18, 2017 at 13:27

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