Regarding the date of issue of form c

a purchasing dealer who is required to avail concessional rate of tax @ 2%, he should issue C form to the seller based on his invoice in order to limit his tax liability in the State of origin. If the purchasing dealer is not providing C form as stated in CST Rule 12(1) specifying the particulars of bill or cash memo or challan such as date, Number and amount, there is every chance to reject the C form by the assessing authority of the seller. In such circumstances, the seller is liable to pay higher rate of tax, interest and penalty. It will create unnecessary litigation between the purchaser and seller. It is most important to note that seller is granting the concessional rate and he is liable to pay tax in the absence of proper C forms. In order to maintain better business relationship, the purchasing dealer is liable to issue the C form on the invoice date. It may kindly note that issue date of the C form is immaterial in this case.

refer the article of  V. DEVENANDA  NARSIMHA (ADVOCATE)