Full definition
PAT test certificate is defined as: A PAT test certificate confirms that portable electrical appliances used by a supplier have been inspected and tested to be electrically safe.
Portable Appliance Testing (PAT) is not a legal requirement in itself, but it is the practical way most UK employers meet their duty under the Electricity at Work Regulations 1989 to keep equipment safe.
Certificates typically list each item, its test result and the next test date. Retest intervals depend on equipment type and environment - construction equipment is tested far more often than office kit.