A major GST compliance shift takes effect on 1 January 2027. Under Notification 04/2026-Central Tax dated 26 October 2026, e-invoicing now applies to domestic reverse-charge purchases from unregistered suppliers and to imports of services.
Tax professionals and accountants must quickly update their daily accounting workflows. You need to handle reverse charge transactions and service imports correctly on the GST portal.
The main goal is mastering self-invoice IRN generation. Getting this right ensures your Input Tax Credit reflects smoothly in GSTR-2B without mismatch issues.
Notification 04/2026-Central Tax & Updated Schema Codes (RCMDOM & RCMIMP)
The regulatory landscape for reverse charge supplies undergoes a major shift with Notification No. 04/2026-Central Tax dated 26 October 2026. This notification amends the principal e-invoicing rules under Rule 48(4) of the Central Goods and Services Tax Rules. Starting 1 January 2027, businesses must generate e-invoices for two new categories of transactions.
The mandate covers domestic reverse-charge purchases from unregistered suppliers and the import of services. Under reverse charge, the registered recipient pays tax directly to the government instead of the supplier. Accountants must prepare to handle these self-accounting entries on the e-invoice portal.
To support this change, the updated e-invoicing schema introduces specialized transaction type codes. The code RCMDOM applies to domestic reverse-charge purchases from unregistered persons. The code RCMIMP applies specifically to the import of services from overseas providers.
For these transactions, the recipient business must generate a compliant self-invoice. This requirement follows Section 31(3)(f) of the CGST Act and Rule 47A. Generating these self-invoices on the portal ensures that your tax records match properly when filing returns.
Turnover Thresholds and the 30-Day IRN Reporting Time Limit
Under the e‑invoicing rules, every regular taxpayer whose aggregate annual turnover (AATO) reaches ₹10 crore or more must adopt e‑invoicing. The threshold is the same for all businesses, regardless of sector, and is measured on the basis of total sales, exempt supplies, exports and inter‑state supplies as recorded in the GST returns.
From 1 April 2025 the GST portal requires these taxpayers to upload each invoice, credit note or debit note to an Invoice Registration Portal (IRP) within 30 days of the document date. The IRP then generates a unique Invoice Reference Number (IRN). The 30‑day window is absolute; if an invoice is uploaded after this period, the IRP will not issue an IRN and the transaction cannot be claimed as a self‑invoice for reverse charge or import of services.
For accountants and CAs this means a tight calendar. A self‑invoice for a reverse‑charge purchase dated 10 January must be uploaded by 9 February. Missing the deadline blocks the IRN permanently, and the GST return will show a missing IRN error that can trigger a filing rejection or a later penalty.
Practical tip: maintain a simple spreadsheet with columns – Invoice No., Invoice Date, Upload Deadline (Invoice Date + 30 days), IRN status. Review it weekly and flag any dates that are about to lapse. For small traders, a reminder on the phone or a quick WhatsApp note can save a day’s work.
Because the IRN is the key identifier for claiming input tax credit on reverse‑charge purchases and imported services, ensuring the 30‑day upload rule is followed safeguards the credit and avoids compliance headaches.
Step-by-Step Procedure to Generate IRNs for Self-Invoices
Generating Invoice Reference Numbers (IRNs) for your reverse charge and import transactions requires a clear, structured approach. Follow these four steps to ensure full compliance under the new mandate.
- Issue a self-invoice: Create a self-invoice under Section 31(3)(f) of the CGST Act and Rule 47A whenever you make a domestic unregistered RCM purchase or import services.
- Assign transaction type codes: In your billing software, select the correct code for your entry. Use RCMDOM for domestic unregistered purchases or RCMIMP for imported services.
- Upload the payload: Submit your self-invoice payload to an Invoice Registration Portal (IRP). The portal validates the data and returns a unique 64-character IRN along with a digitally signed QR code.
- Verify GSTR-2B data: Confirm that the IRN data automatically populates into your GSTR-2B form so you can claim your input tax credit without delays.
Doing this manually can take up too much time and lead to errors. ValueSoft e-Invoice software helps you handle direct bulk IRN generation and prints digitally signed QR codes straight from your bills without needing manual file formatting.
Audit Checklist & GSTR-2B Input Tax Credit Reconciliation
As you prepare for the new e-invoicing mandate starting 1 January 2027, maintaining a solid audit trail is essential for your business and tax compliance. Follow this practical checklist to ensure all self-invoices and reverse charge entries are verified correctly:
- Verify that every physical or digital self-invoice contains the mandatory Invoice Reference Number (IRN) and digitally signed QR code. The buyer must verify this QR code on the physical invoice to confirm its authenticity.
- Audit your vendor registrations carefully to ensure that suppliers marked as unregistered truly lack GSTINs. This step is critical to correctly trigger the RCMDOM schema code.
- Reconcile your self-generated Reverse Charge Mechanism (RCM) IRNs against the auto-populated entries in your GSTR-2B before filing your monthly GSTR-3B return. Remember that the IRN is issued by the Invoice Registration Portal and the invoice data is automatically populated in the recipient's GSTR-2B.
- Maintain strict digital log records of all Invoice Registration Portal (IRP) transaction responses to build a strong defense for your tax audits.
- Utilize the ValueSoft GSTR-2B reconciliation software to auto-match your purchase ledgers, flag any RCM mismatches instantly, and safeguard your valuable Input Tax Credit.
Regular checks protect your business from unexpected tax liabilities and keep your monthly filings clean. For complex cases or specific tax audit queries, speak to your Chartered Accountant.
Final Thoughts
From 1 January 2027 the e‑invoicing rule expands to make self‑invoice reporting mandatory for unregistered reverse‑charge purchases and imported services under Notification 04/2026‑Central Tax. Chartered accountants and tax practitioners must audit client workflows, confirm that every self‑invoice is generated and uploaded within the 30‑day window, and switch to GST‑ready billing software that can create IRNs automatically.
ValueSoft, built by Kala Softech since 1998, is used by over 10,000 businesses and has processed more than 3 million invoices. Its desktop solution works offline, offers flexible backup options, and includes updates and support for the first year. Book a free demo today at https://kalasoftech.com/pricing/ and see how easy compliance can be.
Frequently asked questions
What are RCMDOM and RCMIMP codes in the updated e-invoice schema?
Notification No. 04/2026-Central Tax dated 26 October 2026 amended the e-invoicing notification under Rule 48(4) to include RCMDOM and RCMIMP transaction types. These codes represent domestic reverse-charge purchases from unregistered suppliers and imports of services, respectively. Taxpayers report these self-invoices to an Invoice Registration Portal to obtain an Invoice Reference Number.
How do we issue self-invoices under Section 31(3)(f) with the new e-invoicing rules?
For RCM purchases and import of services, the recipient must generate a self-invoice under Section 31(3)(f) of the CGST Act and Rule 47A. This invoice data is reported to the e-invoicing system via an Invoice Registration Portal to generate an IRN and a digitally signed QR code. Upon generation, the invoice data is automatically populated in the recipient's GSTR-2B.
What happens if we miss generating an IRN for imported services?
Taxpayers with an AATO of ₹10 crore or more must report invoices within 30 days of the invoice date, after which IRN generation is blocked by the system. A valid e-invoice requires an IRN and a digitally signed QR code. Missing this 30-day reporting window prevents IRN issuance and stops automatic population into GSTR-2B.
Sources
- CBIC Expands GST E-Invoicing to RCM Supplies and Import of Services from January 1, 2027
- RCMDOM & RCMIMP from 1 Jan 2027: RCM E-Invoicing Guide
- E-invoice under GST as per Rule 48(4) of CGST Rules 2017
- 5 Years in GST: The impact of e-invoicing in India
- E-invoicing and ITC Claim: Positive Impact of E-invoicing on GST Reconciliation & ITC and blind spots
- E-invoice under GST as per Rule 48(4) of CGST Rules 2017
- What is E-invoicing under GST?
This article is for general information. GST rules change from time to time: check the GST portal or ask your CA before acting on it.
