Test and Tag, or internationally known as "PAT" or "PAT Inspection" 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 testing procedure is not unique to these countries. Similar procedures exist in other countries for example, testing of equipment according to DGUV Vorschrift 3 in Germany.
In Australia and New Zealand, the common name for PAT is simply 'Test and Tag'.
The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and any flexible cables for good condition, and also where required, verification of grounding (earthing) continuity, and a test of the soundness of insulation between the current carrying parts, and any exposed metal that may be touched. The formal limits for pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested.
After testing has determined a pass, a tag is attached to the appliance lead indicating when it was tested, when the next test is due, and a tracking code. Retesting intervals of equipment can vary from 3 months to 5 years, depending of the environment where the equipment is located.