Every telecommunications company must provide pro rata credits to customers of a service whenever that service is billed on a monthly basis and is not available for more than a total of twenty-four hours in a billing cycle. The minimum amount of pro rata credit a company must provide is the monthly cost of service divided by thirty, then multiplied by the number of days or portions of days during which service was not provided.

Pro rata credits are not required when force majeure, customer premises equipment, or inside wiring is the proximate cause for the unavailability of a service. If a company provides a credit amount for unavailable service that is equal to or greater than the credit amount required by this rule, the amount of credit required by this rule need not be provided.