Dear Shri Padmanathan Ji,
On your last post, my views are as follows (Please treat this a pure academic discussion):
I do not agree with your statement that in scenario described by you, "Now the loss of revenue due to the wrong availment of IGST is actually suffered by the State of Kerala (50% Kerala and 50% suffered by Centre)".
A. As PoS is Kelara and transaction is inter-state, Central Govt. got entire revenue of taxes (i.e. IGST) and distribution of that tax will take place as per agreed formula by Centre with State of Kerala. Mode of payment (through utilisation of ITC or cash) does not affect taxes of recipient state.
A1. Similarly, any recovery by Govt. against wrongly availed credit (say, penalty u/s 78 or interest (if payable) besides ubnderlying tax under dispute), state of Kelara will not get any share. All these credits are available to TP as 'Supply Recipient' where PoS is 'State of Maharashtra' (generally speaking & ignoring controversies thereof). Hence, all these benefits (against recoveries) will go Centre & state of Maharashtra, though under which Act, these recovery will take place is matter of dispute under GST, in my view.
B. In my view, for purpose of rule 88B (3), the tax-payer (i.e. TP) who is registered in Maharashtra, has taken wrong credit under head 'IGST' and said ITC is so availed by TP in all three Acts (i.e. IGST, CGST & MGST). In other words, ITC so availed is not in any particular act.
C. Similarly, for purpose of rule 88B (3), said ITC has taken ITC (correctly) under head of CGST & SGST and these ITCs are also availed by him on all three acts listed above and not under any particular Act.
D. Against all ITC claimed by said TP in all three acts, 'balance of credit' available (in total) never fallen below 'wrong availed ITC' and hence, no interest is payable in view (which is explained in more details in my post above at serial No. 2).
E. Now, coming to controversy part - touched by me in Para A1 earlier, please note the followings:
Following questions arises on broader level of discussion (i.e. ignoring limited subject matter is of ITC under the head 'IGST' but taking case of ITC wrongly availed under any of 3 heads):
A. Whether TP had wrongly "availed" ITC under any particular Act i.e. IGST Act, CGSTAct or SGST Act, 2017? And what is legal basis / criteria of such determination?
B. Whether TP had wrongly "utilised" ITC under any particular Act i.e. IGST Act, CGSTAct or SGST Act, 2017? And what is legal basis / criteria of such determination?
C. Is it legally possible that TP had wrongly "availed" ITC under one Act, but wrongly "utilised" it under different Act? And if yes, how SCN should be issued?
And so on .....
Please note that I have not shared any legal views as such in this post (except elaborating my reasoning behind my earliest post at serial no. 2 above and Para A & A1 as answers to your post at serial No. 6), but tried to explain that there are so many areas of conflicting possibilities, further complicated from the fact that the evolving legal jurisprudence of gst provisions / rules are still at their nascent stage.
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.