Is Portable Appliance Testing (PAT) compulsory?

No. The law simply requires an employer to ensure that their electrical equipment is maintained in order to prevent danger. It does not say how this should be done or how often. Employers should take a risk-based approach, considering the type of equipment and what it is being used for. If it is used regularly and moved a lot e.g. a floor cleaner or a kettle, testing (along with visual checks) can be an important part of an effective maintenance regime giving employers confidence that they are doing what is necessary to help them meet their legal duties. HSE provides guidance on how to maintain equipment including the use of PAT.