Recovery of service tax: extended limitation for fraud or evasion and notice, determination, payment and interest rules. The tax authority may serve a show cause notice within the statutory limitation to require payment of unpaid, short paid or erroneously refunded service tax; where defaults are due to fraud, collusion, wilful misstatement, suppression of facts or contravention with intent to evade, limitation is extended. After considering representations, the authority determines the amount payable (not exceeding the notice) and directs payment. Voluntary payment before notice bars subsequent notice for that amount, subject to the officer's power to determine remaining shortfall; interest is payable and voluntary payment attracts no penalty under the Act.