(1) Subject to the first proviso to sub-section (3) of section 16 and first proviso to sub-section (4) of section 18, if a registered dealer, or a dealer who has made an application under sub-section (1) of section 24 within thirty days from the date of incurring liability to pay tax under the Act, sells any goods to any person, he shall issue in the prescribed manner, to the purchaser a serially numbered tax invoice as referred to in clause (48) of section 2, signed and dated by him or his regular employee, showing such particulars as may be prescribed, and he shall also keep a counterfoil or duplicate of such tax invoice, duly signed and dated:

Provided that where the registration certificate of a registered dealer has been cancelled by the appropriate authority from a particular date, or where the application for registration of a dealer as referred to above is rejected from a particular date, any tax invoice issued by such dealer shall be treated as an invoice instead of a tax invoice from that date.

(2) If a dealer to whom sub-section (1) does not apply and who has become liable to pay tax under any provision of this Act, sells any goods to any person, he shall issue in the prescribed manner, to the purchaser a serially numbered invoice or cash memorandum or bill, signed and dated by him or his regular employee, showing such particulars as may be prescribed, and he shall also keep a counterfoil or duplicate of such invoice, cash memorandum or bill, duly signed and dated.

(3) If a dealer to whom sub-section (1) or sub-section (2) does not apply, sells any goods exceeding one hundred rupees in value in any one transaction to any person, he shall issue to the purchaser a serially numbered invoice or cash memorandum or bill, signed and dated by him or his regular employee, showing such particulars as may be prescribed, and he shall also keep a counterfoil or duplicate of such invoice, cash memorandum or bill, duly signed and dated:

Provided that if the State Government is of the opinion that the requirement under this section shall cause hardship to a certain class or classes of dealers included in sub-section (3), and that such requirement should, subject to fulfillment by any class or classes of dealers of certain conditions and restrictions to be imposed to ensure that there is no evasion of tax, be dispensed with, it may prescribe by rules such class or classes of dealers, and such conditions and restrictions subject to which the requirement of this section in respect of such class or classes of dealers shall be dispensed with.

(4) (a) Notwithstanding anything contained elsewhere in the Act, if the Commissioner, on an application made in the prescribed manner, by a registered dealer and after making such enquiries as he may consider necessary, is satisfied that a dealer is not in a position to furnish a tax invoice referred to in sub-section (1) of section 64 on account of the loss of such tax invoice for reasons beyond his control, the Commissioner may, by an order in writing exempt such dealer from furnishing such tax invoice, subject to such conditions as may be prescribed and to such further conditions, if any, as may be specified by the Commissioner in the order.

(b) any order passed by the Commissioner under clause (a) shall be final.