Portable appliance testing

(commonly known as "PAT", "PAT Inspection" or "PAT Testing") is the name of a process in the United Kingdom, the Republic of Ireland, New Zealand and Australia by which electrical appliances are routinely checked for safety. The correct term for the whole process is "in-service inspection & testing of electrical equipment".

Similar procedures exist in other countries, for example, testing of equipment according to BGV A3 in Germany.

Health and safety regulations require that electrical appliances are safe and maintained to prevent harm to workers. Many equipment manufacturers recommend testing at regular intervals to ensure continual safety; the interval between tests depending on both the type of appliance and the environment in which it is to be used. The European Low Voltage Directive governs the manufacture or importation of electrical appliances. Compliance to this has to be declared and indicated by the display of the CE mark on the product. The responsibility for this lies with the manufacturer or the importer and is policed by Trading Standards.

Testing equipment has been specifically developed for PAT inspections, based on the testing equipment used by manufacturers to ensure compliance with the British Standard Code of Practice and European product standards relevant to that type of appliance. This in turn allows testing and the interpretation of results to be de-skilled to a large extent.