As per the provisions of Sec 73 (3) where any service tax has not been levied or paid or has been short-levied or short-paid or erroneously refunded, the person chargeable with the service tax, or the person to whom such tax refund has erroneously been made, may pay the amount of such service tax, chargeable or erroneously refunded, on the basis of his own ascertainment thereof, or on the basis of tax ascertained by a Central Excise Officer before service of notice on him under sub-section (1) in respect of such service tax, and inform the Central Excise Officer of such payment in writing, who, on receipt of such information shall not serve any notice under sub-section (1) in respect of the amount so paid': Expanation to the above provides that no penalty under any of the provisions of the Act or Rules shall be imposed in respect of payment of ST under this sub section except wherein cases of fraud or suppression is involved