Why this matters.
Every employer, and every self-employed person whose work affects others, must keep electrical systems and equipment safe. The Electricity at Work Regulations 1989 require all electrical systems to be built and maintained so far as reasonably practicable to prevent danger (reg.4), and only competent people may carry out electrical work (reg.16). This covers both the fixed installation (wiring, sockets, distribution boards) and portable equipment such as kettles, laptops, extension leads and power tools. The general duties in sections 2 and 3 of the Health and Safety at Work etc. Act 1974 and the risk assessment duty in regulation 3 of the Management of Health and Safety at Work Regulations 1999 sit behind this.
There is no law that says you must PAT test every appliance every year. HSE guidance (INDG236) expects a risk-based approach: user checks, visual inspections and, where the risk justifies it, combined inspection and testing. Getting it wrong can still be costly. Breaches of the 1989 Regulations are criminal offences carrying unlimited fines, electrical fires and shocks can be reportable under RIDDOR 2013, and insurers often ask for evidence of maintenance after a claim. Landlords of private rented homes in England must also have the fixed wiring inspected at least every five years under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, with fines of up to £30,000.