PAT testing explained: what it is, why it matters and how often you need it

PAT testing, short for Portable Appliance Testing, is one of those jobs everyone's heard of but few people can explain. This guide covers what it actually involves, why it matters, who's responsible for it, how often it's really needed, and roughly what it costs.

What is PAT testing?

PAT testing checks that an electrical appliance with a plug, anything from a kettle to a power tool to a photocopier, is safe to keep using. It's a combination of a close visual inspection and a set of electrical tests carried out with a calibrated PAT tester, which measures things you can't see or feel just by looking at an appliance.

A formal visual inspection alone catches the majority of faults: a cracked plug, a frayed cable, a burn mark, a home-made repair. The electrical tests exist for the faults that don't show on the outside, a failing earth path or insulation that's broken down inside the casing, both of which can be lethal even though the appliance looks and works perfectly normally.

Why PAT testing matters

There isn't one single law that names "PAT testing" and sets a fixed interval, which causes a lot of confusion. What does exist is a general legal duty: the Electricity at Work Regulations 1989 require that electrical equipment likely to cause danger is maintained to prevent that danger, so far as reasonably practicable, and the Health and Safety at Work etc. Act 1974 places a broader duty on employers and landlords to keep people safe.

PAT testing is the standard, widely recognised way that businesses and landlords demonstrate they've met that duty. It also matters for a simpler reason: faulty portable appliances are a genuine cause of electric shocks and fires, and most of the dangerous faults aren't visible without a proper inspection and test.

What a PAT test involves

Every appliance goes through the same process:

• Formal visual inspection: the plug, cable, strain relief and casing are checked for damage, wear, an incorrect fuse rating, or signs of a DIY repair.
• Earth continuity: on earthed (Class I) appliances, confirms a sound, low-resistance path to earth so a fault current has somewhere safe to go.
• Insulation resistance: confirms the insulation inside the appliance is sound and not letting current leak through to the casing.
• Polarity: confirms the live, neutral and earth are wired correctly inside the plug.
• Functional check: the appliance is switched on to confirm it operates as it should.

Anything that passes gets a dated label fixed to it, so it's obvious at a glance when it's due again. Anything that fails is taken out of use and reported, with a fixed price to repair or replace it.

Who needs PAT testing?

In practice, it applies to anyone responsible for electrical appliances that other people use:

• Landlords: for any appliances you provide, such as a kettle, toaster or portable heater in a furnished let.
• Employers and businesses: for equipment staff or customers use, from office kettles to power tools.
• HMO landlords: often a specific condition of the property's licence.
• Self-employed tradespeople: for tools used on other people's premises, which many sites won't let you use without a current test label.

Homeowners aren't legally required to test their own appliances, though it's sensible for older or heavily used items.

How often does it need doing?

This is the part with no single right answer. How often an appliance needs testing depends on what it is, how hard it's used and the environment it's in, not a blanket rule that applies to everything you own.

These are sensible starting points, not fixed legal deadlines. A risk-based schedule, testing higher-risk items more often and lower-risk items less often, is both safer and cheaper than testing everything on the same calendar. We'll recommend a schedule for your premises rather than applying one blanket interval.

Rough price guide

PAT testing is priced mainly by how many items need testing. As a rough guide, a small batch of up to 10 items is a flat £95, covering the call-out, travel and testing, and it works out cheaper per item the more appliances you have tested in one visit, which is typical for an office, shop or HMO. See our PAT testing prices for the current guide prices, starting from £2.75 per item for larger batches of 41 or more.

Next steps

Tell us roughly how many appliances you need tested and where, and we'll give you a fixed price and a convenient time. Get a PAT testing quote.