Best Practices for PAT Testing

Doing PAT testing is one thing; doing it well is another. Good practice makes the difference between a testing regime that genuinely keeps a workplace safe and one that just produces stickers. This guide sets out the best practices that make portable appliance testing effective, from prioritising the visual inspection to keeping records that stand up to scrutiny.

Start with a thorough visual inspection

The single most important best practice is to take the visual inspection seriously, because most faults are found by looking, not by the tester. A careful check of the plug, fuse, flex, anchorage and casing catches damage that the electrical tests would never reveal, and it catches it quickly. Rushing the visual stage to get to the instrument is a false economy. A competent inspector who looks properly will fail unsafe items that a tester alone would pass.

Use a competent person and a calibrated tester

Testing should be carried out by a competent person, someone trained to recognise faults, choose the right tests and interpret the results. Competence is what turns a pass or fail into a sound judgement. Equally, the tester itself must be trustworthy, which means keeping it calibrated. An uncalibrated tester can pass unsafe equipment or fail good equipment, undermining the whole exercise. Competence and calibration together are what make results reliable.

Test on a risk-based schedule

Best practice sets testing frequency by risk, not by a blanket calendar rule. Consider the type of equipment and its environment: a power tool on a site, exposed to damage and damp, needs far more frequent checking than a computer in an office. Combining frequent user checks and periodic visual inspection with combined testing at sensible intervals gives good coverage without wasting effort where it is not needed.

Keep thorough records

Records are what make a testing regime defensible and manageable. Good record keeping captures the essentials for every item.

Maintaining an appliance register, and using a tester that downloads results into software, removes the paperwork burden and keeps everything traceable. Labelling passed items clearly completes the picture.

Act on failures, and do not over-test

A failed item must be taken out of use immediately and repaired or replaced, then re-tested before it returns to service. Acting decisively on failures is the whole point of testing. At the same time, best practice avoids over-testing, checking low-risk equipment far more often than the risk justifies wastes time and money without adding safety. The goal is proportionate, effective testing, not maximum testing.

FAQs

Why is the visual inspection so important?

Because most faults are found by looking rather than by the instrument. A careful check of the plug, fuse, flex and casing catches damage the electrical tests cannot, and it does so quickly. A thorough visual inspection is the foundation of effective testing.

What records should you keep?

For each item: a unique asset ID and description, the test date and result, the next test date, and the tester and readings. An appliance register and downloadable results keep this manageable and provide a defensible audit trail.

Can you test too often?

Yes. Over-testing low-risk equipment wastes time and money without improving safety. Best practice matches frequency to risk, so effort goes where it genuinely reduces danger.

Good practice is what turns testing into real safety. Talk to us about the right tester, training and calibration to do PAT testing properly.