Dear Mr. Raja,
Apologies if you feel the other way around, but its not my intention. Please use the terms "as per my view / in my view" when ever a cross view is raised after other author expresses their view if no legal back up was brought in support. I feel no one including me has the right to override the views expressed by other authors, with out bringing any supporting legal back up.
In simple to understand section 16(4) i'm placing here with the FAQ release by CBIC below (Refer Final-GST-FAQ-31218 issued by CBIC):
Q 17. What is the time limit for taking ITC and reasons therefor?
Ans. A registered person cannot take ITC in respect of any invoice or debit note for supply of goods or services after the due date for furnishing the return under section 39 for the month of September following the end of financial year to which such invoice/invoice relating to debit note pertains or furnishing of the relevant annual return, whichever is earlier. So, the upper time limit for taking ITC is 20th October of the next FY or the date of filing of annual return whichever is earlier.
The underlying reasoning for this restriction is that no change in return is permitted after September of next FY. If annual return is filed before the month of September, then no change can be made after filing of annual return.
Ms. Roshini, please refer press-release-on-Annual-Return-GST-141119 dated 14th Nov 2019 read with relevant notification, the due date for filing Annual return for FY 18-19 has been extended till 31st Mar 2020.