QUESTION
Suppose we generate tax invoice as on 31st July, 2019 but material actually dispatched on 10th August 2019 with e-way bill (dated 10th august 2019). in this case  to know whether such transaction is valid under GST act or not? if yes how much days difference are allowed between invoice and e-way bill?
 

ANSWER
Law Applicable: SECTION 31 OF CGST ACT
(1) A registered person supplying taxable goods shall, before or at the time of,'
a) removal of goods for supply to the recipient, where the supply involves movement of goods; or
b) delivery of goods or making available thereof to the recipient, in any other case, issue a tax invoice showing the description, quantity and value of goods, the tax charged thereon and such other particulars as may be prescribed

CGST RULE 138

(1) Every registered person who causes movement of goods of consignment value exceeding fifty thousand rupees'
(i) in relation to a supply; or
(ii) for reasons other than supply; or
(iii) due to inward supply from an unregistered person, shall, before commencement of such movement, furnish information relating to the said goods as specified in Part A of FORM GST EWB-01 , electronically, on the common portal along with such other information as may be required on the common portal and a unique number will be generated on the said portal:

Interpretation: In your case as the invoice is generated on 31st JULY, 2019 BUT MATERIAL ACTUALLY DISPATCHED ON 10th AUGUST 2019, therefore E Way bill should be generated on the date of actual dispatch i.e. 10th AUGUST 2019 so that the validity period of E Way bill will not expire. These transactions are valid in GST Act because there is no maximum time limit specified in Act within which E Way Bill must be generated from the date of tax invoice.

Conclusion: There is no maximum time limit specified in Act within which E Way Bill must be generated from the date of tax invoice. There is a possibility that the transporting vehicle might be stopped on the way and GST Officer questions about the difference in invoice date and E Way bill date and he will get motivated to further investigate in your case. So to avoid further investigation you will have to justify why you did not dispatch goods for such a long period.