(1) Where for any year or part thereof, the Assessing Authority has reason to believe that the whole or any part of turnover or tax of the dealer in respect of any tax period has-

(a) escaped assessment; or

(b) been under assessed; or

(c) been assessed at a rate lower than the rate at which it is assessable; or

(d) been wrongly allowed any exemption or deduction therefrom; or

(dd) During Assessment rebate or concession has been allowed on the basis of submitted declaration form or certificate but such submitted declaration form or certificate is found to be false or wrong, afterwards; or

(e) been wrongly allowed any tax credit therein,

the assessing authority shall, after recording the reasons in writing, serve a notice on the dealer and after giving the dealer a reasonable opportunity of being heard and making such enquiries as he considers necessary, he shall assess or reassess the turnover of the dealer and tax according to law and the provisions of this Act shall as far as may be, apply accordingly:

Provided that the tax shall be charged at the rate at which it would have been charged had the turnover not escaped assessment or full assessment as the case may be.

Explanation (1): Nothing in this sub-section shall be deemed to prevent the assessing authority from making an assessment to the best of its judgment.

Explanation (2): For the purposes of this section and of section 30,"Assessing Authority" means the officer who passed the earlier assessment order, if any, and includes the officer having jurisdiction for the time being to assess the dealer.

Explanation (3): Notwithstanding the issuance of notice under this sub-section, where an order of assessment or reassessment is in existence from before the issuance of such notice it shall continue to be effective as such, until varied by an order of assessment or reassessment made under this section in pursuance of such notice.

(2) Except as otherwise provided in section 28 or under this section, no order of assessment or reassessment shall be made under sub-section (1) after the expiry of three years form the end of the year in respect of which or part of which the tax is assessable.

(3) Assessment or reassessment in respect of turnover escaped from assessment may be passed at any time within three years and nine months ending on 31^st December after the expiry of assessment year for which assessment is to be made, provided that notice under this section has been served within a period of three years and six months ending on 30^th September after the expiry of the assessment year for which assessment is to be made.

(4) If the Commissioner on his own or on the basis of reasons recorded by the Assessing Authority is satisfied that it is just and expedient so to do, he may authorise the Assessing Authority in that behalf, and then such assessment or reassessment not made after the expiration of six years after the end of such assessment year or after the expiration of four year from the date of the order sought to be reassessed, whichever is later notwithstanding that such assessment or reassessment may involve a change of opinion.