(1) Subject to the provisions of rule 30D, where a dealer, not being a dealer who has exercised option to pay tax at compounded rate under sub-section (3) of section 16 or under sub-section (4) of section 18, claims to have made sale of goods in West Bengal immediately preceding the sale in the course of export within the meaning of sub-section (3) of section 5 of the Central Sales Tax Act. 1956 (74 of 1956) and intends to claim deduction under clause (b) of sub-section (1) of section 16 of such sales from his turnover of sale, he shall, on demand by the appropriate auditing authority or the appropriate assessing authority, furnish a declaration in Form 12A duly filled in and signed by the purchasing registered dealer along with evidence therefor referred to in the Schedule to such declaration.

(2) The declaration in Form 12A shall be obtained from the appropriate assessing authority or the officer authorised by the Commissioner for such purpose as referred to in rule 301, in accordance with the provision of the rule 30H by the purchasing dealer to whom a sale referred to in sub-rule (1) is made.

(3) The purchasing dealer shall certify in the declaration in Form 12A, inter alia, that the goods purchased from the selling dealer referred to in sub-rule (1) have been exported out of the territory of India within the meaning of sub-section (1) of section 5 of the Central Sales Tax Act, 1956 (74 of 1956):

Provided that no single declaration in Form 12A shall cover particulars of more than one transaction of sale of goods, which have been exported by the purchasing dealer out of the territory of India.

(4) Any declaration in Form 12 A furnished by the selling dealer in contravention of the provision of sub-rule (2), or sub-rule (3), of this rule or rule 30E, in respect of the last sale immediately preceding the sale in the course of export, shall not entitle the selling dealer to claim deduction under clause (b) of sub-section (1) of section 16 in respect of sales referred to in sub-rule (1).