Service tax liability deemed for customers of agents and transport operators; retroactive self-assessment return requirement imposed. Customers engaging clearing and forwarding agents and persons paying freight to goods transport operators are deemed retrospectively to have been liable to pay service tax for specified past periods. Those deemed liable must furnish a self-assessed return to the Central Excise Officer within six months of the Finance Bill, 2003 receiving presidential assent, notwithstanding earlier return provisions. The amendment also provides for prescribing the manner of furnishing the return under the new transitional provision.