Retrospective validation of tour operator service tax exemption enables refunds, subject to a six month claim deadline and refund procedure. The measure validates retrospectively a notification exempting tour operator services by holders of contract carriage permits for inter state or intra state passenger transportation (excluding tourism, conducted tour, charter or hire) from service tax from 1 April 2000. It mandates refunds of tax collected that would not have been payable had the exemption applied, requires refund claims within six months of the Finance Bill receiving presidential assent, and makes applicable the Central Excise refund procedure for administration of such refunds.