Issuance of summons under Section 70 of the CGST Act does not constitute initiation of "proceedings" under Section 6(2)(b), which requires issuance of a formal show cause notice. (!) [judgement_subject][judgement_act_referred][1][2][8][9][20][21][59][62]

Summons are preliminary inquiries for information gathering, distinct from substantive proceedings like assessment or demand under Sections 73 or 74. (!) (!) [23][24][57][58][59][62]

Section 6(2)(b) bars parallel proceedings on the same subject matter only after one authority has initiated proceedings via show cause notice; it does not apply to summons, searches, or seizures. (!) (!) [59][61][72][96 vi]

"Proceedings" under Section 6(2)(b) commence with issuance of a show cause notice, which sets out charges, grounds, and proposed demands, leading to adjudication. (!) (!) (!) (!) (!) (!) (!) [72][73][96 vi]

Intelligence-based enforcement actions can be initiated by either Central or State authorities across the taxpayer base, irrespective of administrative assignment, and must be taken to logical conclusion by the initiating authority. (!) (!) (!) (!) (!) (!) (!) [96 iii][96 iv]

Single interface divides taxpayers between Central and State administrations for routine functions like audits and scrutiny, but cross-empowerment allows enforcement on intelligence. (!) (!) (!) (!) [96 ii]

"Subject matter" under Section 6(2)(b) refers to the specific tax liability, deficiency, or contravention detailed in a show cause notice; summons do not define it sufficiently. (!) (!) (!) (!) (!) (!) (!) [96 vii][96 viii]

Test for "same subject matter": (1) identical tax liability or offence on same facts; (2) identical demand or relief sought. (!) [96 x]

Where overlapping inquiries arise, authorities must coordinate: assessee informs subsequent authority; authorities verify and decide which proceeds, forwarding materials if needed; first-initiated authority prevails if no agreement.[97]

Proper officer issuing order under CGST Act must issue corresponding order under SGST/UTGST Act, intimating jurisdictional officer, to avoid multiplicity. (!) (!) (!) [96 i]

Guidelines mandate assessee cooperation with summons; authorities share intelligence via IT systems to prevent duplication.[97][98][99]

Special Leave Petition dismissed, upholding High Court order declining interference with summons.[1][2][7][96][100]