Extension (or Extension of Cover) is an additional coverage provision that broadens the scope of protection beyond the standard insuring clause, either included automatically or available for additional premium. Extensions may expand what is covered (such as defence costs for regulatory investigations), who is insured (such as subsidiaries or former employees), the territorial scope, or the time period for claims. These provisions typically operate subject to their own sub-limits, conditions, and exclusions, which may be more restrictive than the primary coverage. Extensions allow insureds to customise policies to address specific exposures without purchasing separate standalone coverage.