(1) Every registered dealer shall file a tax return for each tax period within fifteen days after end of the period in such manner as may be prescribed.

(2) The returns submitted by the dealer along with tax due thereon shall be accepted as self-assessed:

Provided that the assessing authority may select either at his discretion or as directed by the Commissioner, any dealer for detailed assessment for a tax period or tax periods by scrutiny of accounts and may make best judgement assessment if so required, where-

(a) a person fails to file a return as required under sub-section (1); or

(b) the assessing authority is not satisfied with the correctness and completeness of a return filed by a person; or

(c) the Commissioner has reasonable ground to believe that a person will become liable to pay tax under this Act but is unlikely to pay the amount due.

(3) When making any assessment under sub-section (2), the assessing authority may also direct the dealer to pay in addition to the tax assessed, a penalty not exceeding double the amount of tax due on the turnover that was not disclosed by the dealer in his return or, in the case of failure to submit a return, double the amount of tax assessed, as the case may be:

Provided that before taking action under this sub-section, the dealer shall be given a reasonable opportunity of being heard.

(4) The assessing authority shall serve a notice of assessment on completion of assessment under this section and the dealer shall pay the balance of tax in accordance with the terms of that notice.

(5) Subject to sub-section (6) of this section, no assessment under this section for any year shall be made after a period of three years from the end of the year to which the return under this Act relates.

(6) Where, for any reason, the input tax credit has been availed wrongly or where any dealer produces false invoice, vouchers, declaration certificate or any other documents with a view to support his claim of input tax credit or refund, the assessing authority shall, at any time, within a period of five years from the end of the year to which the return relates, reverse input tax credit availed and determine the tax due after making such an enquiry as it may consider necessary:

Provided that no order shall be passed under this sub-section without giving the dealer a reasonable opportunity to show cause against such order.