Typically any electrical item that has a power lead that is plugged into a power point needs to be inspected, tested and tagged on a regular basis.
For some types of equipment or electrical items, the frequency of testing is more often where there is a higher safety risk or where there is likely to be greater use and wear. For example, a tradesman or a carpenter has a higher risk factor and needs to have their electrical equipment tested more often than a computer in a standard office.
There are some types of items and equipment like “hard wired” electrical fittings that do not need to be tested and tagged.