Thanks, Shri Sadanand Sadabule Ji for sharing your views.
Now, as desired by you, I am elaborating my conflicting views from my post at Sr. No. 2 above and same reads as follows:
Changing / modifying E-invoice dated 08.01.2024 while filing Form GSTR-1 for Jan, 24 may lead to its own sets of potential challenges in my view.
A. Considering that tax-payer had raised E-invoice dated 08.01.2024, I am presuming that he is falling into 'specified class of persons' who are bound to do so compulsorily as per Rule 48(4) of CGST Rules, 2017.
A1. As per Rule 48(5), if such specified class of persons do not issue E-invoice, then, invoice otherwise issued by him (i.e. without obtaining an Invoice Reference Number by uploading information contained therein on the Common Goods and Services Tax Electronic Portal) will not be treated as invoice under GST law.
A2. One of the conditions to avail ITC by the recipient tax-payer in given situation is that 'he is in possession of a tax invoice or debit note issued by a supplier registered under this Act' as per Section 16(2)(a). It is worth noting that this condition is in addition to condition that 'the details of the invoice or debit note referred to in clause (a) has been furnished by the supplier in the statement of outward supplies and such details have been communicated to the recipient of such invoice or debit note in the manner specified under section 37u/s 16(2)aa).
A3. In other words, mere availability on invoice-details in Form GSTR-2B at the recipient's end is not sufficient to take ITC in absence to having valid e-invoice issued by the supplier in given situation.
A4. If supplier chose to 'Changing / modifying E-invoice dated 08.01.2024 while filing Form GSTR-1 for Jan, 24' (instead of 'Issuance of Credit-note u/s 34 and then, fresh e-invoice showing inter-state sale & correct showing correct particulars including IGST payable, which is my suggested course of action in my post at Sr. No. 2 above), it means that supplier failed to issue 'Invoice under GST Law' to the recipient and the recipient will not be to fulfill condition u/s 16(2)(a).
A5. This in-turn may lead to denial of ITC to the recipient. This was my primary concern while positing conflicting view in my earlier post.
B. Another, though to a smaller extent, concern I have (i.e. if supplier chose to 'Changing / modifying E-invoice dated 08.01.2024 while filing Form GSTR-1 for Jan, 24' instead of process suggested by me) is that there will be mis-match in sales shown by the supplier through e-invoice and sales reported in Form GSTR-1. This may lead to needless inquiry against the supplier by Dept. in future.
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.