All electrical installations deteriorate with age and use. They should therefore be inspected and tested at regular intervals to check whether they are in a satisfactory condition for continued use. Such safety checks are commonly referred to as 'periodic inspection and testing'.
A periodic inspection will reveal if any of your electrical circuits or equipment are overloaded, find any potential electric shock risks and fire hazards, identify any defective electrical work, highlight any lack of earthing or bonding. Periodic inspection and testing should be carried out only by electrically competent persons, such as registered engineers. They will check the condition of the electrics against the NFPA standard for the safety of electrical installations.
The competent person will then issue an Electrical Installation Condition Report detailing any observed damage, deterioration, defects, dangerous conditions and any non-compliance with the present-day safety standard that might give rise to danger. If anything dangerous or potentially dangerous is found, the overall condition of the electrical installation will be declared to be 'unsatisfactory', meaning that remedial action is required without delay to remove the risks to those in the premises.