Mandatory E-Invoicing for Inward RCM & Scrap RCM Extension (Notification No. 04/2026 – Central Tax): Complete Compliance Guide for CAs & CFOs

Introduction to Notification No. 04/2026 – Central Tax

The Central Board of Indirect Taxes and Customs (CBIC) has issued Notification No. 04/2026 – Central Tax, marking a significant escalation in India's indirect tax compliance architecture. This legislative update introduces two major regulatory shifts: the institutionalization of mandatory e-invoicing for inward supplies liable to Reverse Charge Mechanism (RCM), and the statutory extension of RCM to four vulnerable scrap and waste categories. For Chief Financial Officers (CFOs), Chartered Accountants (CAs), and indirect tax heads, this directive demands immediate structural alignment of enterprise resource planning (ERP) systems, vendor onboarding workflows, and Input Tax Credit (ITC) matching mechanisms ahead of the enforcement deadlines.

Section 1: Statutory Framework & Legal Background

To fully comprehend the operational impact of Notification No. 04/2026, practitioners must analyze its intersection with the core provisions of the Central Goods and Services Tax (CGST) Act, 2017:

• Section 9(3) and 9(4) of the CGST Act, 2017: Empowers the government to specify categories of supply of goods or services wherein the tax shall be paid on a reverse charge basis by the recipient, including supplies received from unregistered suppliers.
• Section 31(3)(f) of the CGST Act, 2017: Mandates that a registered person who receives a taxable supply from an unregistered supplier shall issue an invoice in respect of such supply on the date of receipt of supplies (Self-Invoice under RCM).
• Rule 48(4) of the CGST Rules, 2017: Governs the generation of electronic invoices through the Invoice Registration Portal (IRP), which is now being expanded to encompass inward RCM documentation and self-invoicing flows.

Penalties & Non-Compliance Consequences: Failure to generate mandatory e-invoices for RCM transactions or incorrect reporting in GSTR-3B attracts penal provisions under Section 122 of the CGST Act, carrying a penalty of INR 10,000 or an amount equivalent to the tax evaded, whichever is higher, per offense. Furthermore, any failure to account for inward RCM self-invoices directly jeopardizes the admissibility of ITC under Section 16(2), alongside exposure to interest under Section 50 at 18% per annum on delayed tax remittances.

Section 2: Scope of Expansion & Applicability Matrix

The regulatory framework operates across two distinct timelines and operational scopes:

1. Extension of RCM to 4 New Scrap Categories (Effective 1 November 2026)

Registered buyers acquiring specific secondary raw materials from unregistered suppliers must self-account and remit GST under RCM. The notified categories include:

• Tyre waste and scrap
• E-waste and scrap
• Plastic waste and scrap
• Used cooking oil

2. Mandatory E-Invoicing for Inward RCM (Effective 1 January 2027)

Businesses falling within notified turnover brackets must generate a valid Invoice Reference Number (IRN) and QR code via the IRP for self-invoices issued under Section 31(3)(f) for all inward RCM supplies, bridging the historical compliance visibility gap between registered recipients and unregistered providers.

Section 3: Step-by-Step Operational & ERP Workflow

Transitioning to the dual mandate of scrap RCM and inward RCM e-invoicing requires an automated, systematic intervention across organizational workflows:

1. Vendor Master Classification: Audit and tag all suppliers in the ERP (SAP, Oracle, Microsoft Dynamics, or custom setups) as 'Registered' or 'Unregistered' (URD), with mandatory sub-classification for scrap dealers dealing in tyres, e-waste, plastics, and used cooking oil.
2. Automated Self-Invoice Generation: Configure the ERP to automatically trigger a self-invoice format meeting Rule 46 requirements upon Goods Receipt Note (GRN) creation for URD purchases.
3. IRP Integration for Inward RCM: Establish API integration with the Invoice Registration Portal to push self-invoice JSON payloads, capturing valid IRNs and signed QR codes before month-end closing.
4. RCM Ledger Posting & Tax Liability Mapping: Ensure automated debit of RCM liability ledger and corresponding credit of eligible ITC in GSTR-3B Table 3.1(d) and Table 4(A)(2) without manual intervention.
5. Reconciliation and Audit Trail: Implement monthly automated reconciliations between internal RCM self-invoices, GSTR-2B, and GSTR-3B filings to eliminate mismatch disclosures and audit queries.

Section 4: Compliance Impact Comparison

The following table delineates the operational shift from historical practices to the strict mandates introduced by Notification No. 04/2026:

Section 5: Action Plan Checklist for Finance & Audit Teams

CAs, tax directors, and internal audit committees should execute the following 5-point action plan immediately:

• ✔ Conduct URD Vendor Audit: Review all vendor contracts, PAN details, and GST status, specifically identifying suppliers dealing in the 4 newly notified scrap categories before 1 November 2026.
• ✔ Upgrade ERP & IT Infrastructure: Coordinate with IT vendors to configure auto-generation of self-invoices and establish direct API connectivity with the IRP for inward RCM before 1 January 2027.
• ✔ Revise Standard Operating Procedures (SOPs): Update internal procurement and accounts payable manuals to mandate URD purchase approvals and tax deposit verifications prior to payment release.
• ✔ Train Procurement & Accounts Payable Teams: Conduct specialized workshops for buying agents and finance personnel regarding the legal implications of purchasing scrap from unregistered dealers.
• ✔ Perform Mock Run Reconciliations: Run simulated monthly compliance cycles to test inward RCM e-invoice generation, ledger postings, and GSTR-3B reporting accuracy prior to statutory deadlines.