Is hard wire testing the same as fixed wire testing?

Electricity’s a magical thing. Powerful, wonderful, moderately mysterious. Treat it badly, it’ll kill you stone dead or burn your eyebrows off. Treat it well, and it’ll power all the things you want in the 21st century.

Well, true love, world peace, happily ever after, fine – no analogy is perfect. But certainly, electricity powers most of the things you want in the 21st century.

Certainly, it’s the backbone of modern business, and without it, business in the age of the computer would look very different. There’d be a lot more crank handles, for a start, and probably the occasional monkey on a bike for when you needed to send a particularly hefty email.

There’s electricity though, and there’s electricity.

And in particular, there’s wiring…and then there’s wiring.

Some businesses regularly get a hard wire test. Others regularly get a fixed wire test.

Can you tell the difference?

Can anyone?

The answer is by no means as straightforward as you might think. It makes only partial sense at best, but let’s break it down.

The Laptop Is A Portable World

It’s important to say right away that there’s less of a difference between hard wire testing and fixed wire testing than there is between either of those options and portable appliance testing.

It’s as well to get portable appliance testing out of the way as soon as possible, because it frequently gets in the way and confuses people.

Portable appliance testing, as the name goes pretty far out of its way to imply, is for portable devices. Phone chargers, kettles, laptops. All the kit that you regularly do or regularly could pick up and move about the place – is a portable appliance. To check the electrical resilience and performance of all that equipment, go with a portable appliance test.

That’s what gives you the little mysterious stickers on everything you use, to prove that – at least in the absence of sudden terminal obsolescence, or possibly an encounter with the Norse god of thunder, they’re not about to suddenly explode on you.

Don’t underestimate the importance of portable appliance testing, because no-one likes an exploding laptop outside a Penn and Teller show. Just don’t get it confused with either fixed wire testing or hard wire testing.

The Hardcore Testing

Fixed wire testing and hard wire testing are both concerned with what might be described as the hardcore gubbins of your business and your building. The wiring diagrams of the whole building, and how the building is connected to the mains supply and the national grid are the business of both hard wire and fixed wire testing.

They’re both concerned with the power supply to the sockets, the outlets, the lights – all the infrastructure power connections that mean when you turn on the lights or plug in the laptops, they do more than just sit there in a zero-power sulk.

But are they the same?

Well…yes. And yet, at the same time…no.

It’s All About The Sprinkles

They’re the same in the same way that ice cream and an ice cream sundae are the same. It’s one of those ‘All fixed wire tests are hard wire tests, but not all hard wire tests are fixed wire tests…’ deals.

The tricky thing is they’re both the same in at least some of their essentials, to the point where they’ve been regarded as the same thing.

In fact, plenty of installers and testers will tell you they’re the same to this day. And the point is, some testers mean them as the same thing.


So are most people. Here’s how it breaks down.

  Hard Wire Versus Fixed Wire

Hard wire testing tests the hard wires inside your infrastructure. At minimum. It tests them to ensure they comply with the scorching bestseller that is the Health and Safety Work Act (1974), and the more genre but also more commercial Electricity At Work Regulations (1989).

Where things get complicated is that there’s more to a fixed wire test than just testing the hard wires.

Subject to the same regulations for the safety of staff and the visiting public, fixed wire testing routinely tests:

  • Hard wiring and connections

  • Distribution boards and switchboards

  • Fuses, circuit breakers and RCDs

  • Lighting socket outlets

  • Air conditioning

  • Fixed plant

Ice cream and ice cream sundaes, right? Hard wiring tests check your ice cream – the hard wiring that takes the power safely from the grid to the sockets. Fixed wire testing tests that too – and then adds on the wafers of switchboards, the chocolate sauce of fuses, the whipped cream of lighting socket outlets…

You get the point.

The Name Game

Where it gets extra complicated is that plenty of installers and testers…test the whole electric sundae…and call it a hard wire test.

Which is where the confusion probably comes from.

Bottom line, a hard wiring test only needs to test the hard wiring. It can include all the rest, and if it does, some call it a hard wiring test, and some a fixed wiring test.

The slight additional complication is that a fixed wire test is a moveable feast too.

You pretty much expected that by now, didn’t you?

Some companies demand 100% of their circuits be tested along with the hard wiring in order to consider they’ve had a full fixed wiring test.

Some on the other hand, prefer a rolling 20% or 33% test, complying with options for either 5 year or 3 year testing frequency.

 The Paperwork

One of the supposedly differentiating factors between a fixed wire test and a hard wire test is that the fixed wire test gets you an Electrical Installation Condition Report (EICR) when it’s completed, certifying your whole electrical system as safe under the Electricity at Work Regulations 1989.

But the likelihood is that some testers and some clients understand a hard wire test which also tests all the circuits and the other elements is a fixed wire test, and so the testers give out the correct report to those clients. While still calling it a hard wire test, rather than a fixed wire test.

The upshot is that sometimes, a hard wire test and a fixed wire test are the same thing. But they’re not at point required to be the same thing, and it’s always worth checking what you’re getting for your wiring test money, because sometimes the hard wire test will get you significantly less certainty than the fixed wire test you may be expecting.

Close up of green cables

Is hard wire testing the same as fixed wire testing?


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