PAT testing explained: what it is and how often you really need it

Portable appliance testing, commonly called PAT, is a way to check whether portable electrical equipment remains safe to use. Depending on the equipment, this may involve a visual inspection and electrical tests. It is one part of a maintenance system, not a certificate that guarantees an appliance can never become dangerous.

In Great Britain, the Electricity at Work Regulations 1989 require electrical systems to be maintained, so far as is necessary to prevent danger. Northern Ireland employers should check their corresponding rules. The GB Regulations do not prescribe an annual PAT test for every appliance. HSE's PAT explanation says the Regulations do not specify what must be done, by whom or how often, and do not make inspection or testing of electrical appliances an automatic annual legal requirement. That distinction matters for offices, workshops, construction sites and rented equipment with very different exposure patterns.

What should be checked?

Start with a user check: obvious damage to the plug, cable or case, signs of overheating, a loose connection, or an unsafe environment. A trained person can conduct a more formal visual inspection for defects users may miss. Electrical testing may then be appropriate for some equipment and environments. A test cannot replace a visual inspection, because a damaged cable or unsuitable use may be apparent even if an instrument produces a passing number.

Consider how the equipment is used and moved. A stationary monitor in a dry office is not exposed to the same damage as a power tool carried between outdoor work areas. Think about equipment class, cable condition, environment, frequency of movement, previous defects and manufacturer instructions. HSE's INDG236 guidance explains a risk-based approach for low-risk environments. Higher-risk activities can need a different maintenance regime.

How often should PAT be done?

There is no universal number of months. Choose a check and inspection pattern from the risk assessment and experience. If repeated checks find defects, investigate why and whether the interval or controls need changing. If equipment stays in a low-risk location with no defects, an annual combined test may add little value. If it is repeatedly damaged, waiting for a calendar anniversary may be too slow. Document the reasoning so the interval can be revisited.

Do not translate a client's contractual annual-test rule into a universal legal rule. A customer, insurer, landlord or site manager may impose a specific condition. It may be binding in that relationship, but it is different from the statutory baseline. Likewise, a label with a due date is a useful management aid where the organization chooses to use one; HSE says the Regulations do not require labels or records of inspection and test in every case.

Who can inspect or test?

The person needs competence for the task. Simple user checks require clear instruction about what to look for and what to do with damaged equipment. Formal inspections and instrument testing require a person who understands the equipment, defects and appropriate methods. Owning a test instrument is not the same as being competent to interpret results. Remove suspect equipment from use and arrange repair or replacement by an appropriate person.

Where records are used, connect each item to a unique identifier, location, check date, result, defects, corrective action and next review. Keep the reason for an interval change. A missed test date should trigger investigation, but it does not by itself prove a breach of a universal annual PAT law. The certificate renewal calculator can help plan a chosen review date; it does not decide the legally sufficient interval.

The PAT testing software page is the commercial route for teams evaluating a wider tracking process. This page does not claim Complys tests equipment, issues a legal certificate, or sets safe intervals automatically.

General information, not legal advice. Verify current requirements against the primary sources linked above.