Section 32(12) in Kerala General Sales Tax Rules, 1963
(12)Every such bill or cash memorandum shall be prepared in duplicate serially machine-numbered, one copy of it shall be issued to the purchaser and the other copy shall be retained by the dealer. The serial numbers assigned to the bills or cash memoranda shall run consecutively for the whole year. Where a dealer maintains separate series of bills or cash memoranda for different classes of goods, such dealer may use different series with the alphabets, A, B, C, etc., prefixed to each series. The dealer shall intimate the series and the opening numbers of Bills of cash memoranda intended to be used by him in a year to the assessing authority during the month of April and the last number of bills or cash memoranda issued shall be noted in the annual return relating to the year.
