Receiving a standard paper or PDF invoice from a large or mid-sized vendor is a common trap during monthly reconciliation. If that vendor falls under the mandatory e-invoicing threshold, an invoice without an IRN and a signed QR code is legally void for GST credit purposes, even if you paid the vendor in full.
Legal status under Rule 48(5) and Section 16(2)
The requirement to obtain an Invoice Reference Number is governed by Rule 48(4) of the CGST Rules, which mandates notified taxpayers to prepare invoices by uploading particulars in Form GST INV-01 on the e-invoice portal. The consequence of skipping this process is clear under Rule 48(5) of the CGST Rules: every invoice issued by a person to whom Rule 48(4) applies in any manner other than obtaining an IRN shall not be treated as an invoice.
To claim input tax credit under Section 16(2)(a) of the CGST Act, a registered recipient must be in possession of a valid tax invoice or debit note. When Rule 48(5) strips an unauthenticated document of its status as an invoice, the recipient fails the very first condition of Section 16(2). Even if the supplier manually reported the bill in GSTR-1, the recipient does not hold a valid tax-paying document in the eyes of the law. You can review the complete eligibility framework in our guide on input tax credit conditions under GST.
Notice risk: Claiming ITC on an invoice without an IRN from a notified supplier violates Section 16(2)(a). During an audit or scrutiny, the tax officer can disallow the credit, demand immediate repayment, and levy interest under Section 50.
What happens if the invoice appears in GSTR-2B?
A supplier who forgets to generate an IRN on the e-invoice registration portal might still manually type the invoice details into Form GSTR-1 before filing. According to GSTN GSTR-1 portal guidelines, e-invoices auto-populate into Tables 4A, 4B, 4C, 6B, and 6C, but the portal still permits manual entries. When the supplier files GSTR-1 manually, the document passes into your GSTR-2B.
Meeting the GSTR-2B condition under Section 16(2)(aa) does not exempt you from Section 16(2)(a). All conditions of Section 16(2) operate simultaneously. If the primary invoice is invalid under Rule 48(5), having the entry reflected in GSTR-2B does not cure the defect.
Using the Invoice Management System on the GST portal, recipients can mark questionable invoices as Pending or Rejected rather than accepting them blindly. This prevents premature credit availment until the vendor provides a regularized e-invoice.
Worked example: checking vendor compliance
Consider an enterprise, Bharat Tech Solutions, procuring IT hardware from Apex Systems Pvt Ltd in October 2026. Apex Systems is a notified taxpayer with aggregate turnover exceeding the e-invoicing threshold.
| Invoice number | Taxable value | IGST (18%) | IRN status | In GSTR-2B | Action required |
|---|---|---|---|---|---|
| INV-1081 | ₹2,00,000 | ₹36,000 | Missing | Yes (manual entry) | Do not claim ITC; request IRN |
| INV-1082 | ₹1,50,000 | ₹27,000 | Valid IRN present | Yes (auto-populated) | Eligible for ITC claim |
For invoice INV-1081, the tax amount of ₹36,000 cannot be claimed in Table 4(A)(5) of Form GSTR-3B. If claimed, the company risks a recovery demand for ₹36,000 plus interest under Section 50 at 18% per annum from the date of utilisation until repayment.
Calculation of potential interest exposure if ₹36,000 is wrongly claimed and retained for 90 days:
Interest = ₹36,000 × (18 / 100) × (90 / 365) = ₹1,598.
How to request a valid e-invoice from your vendor
When you discover an invoice without an IRN, contact the supplier accounts team immediately before your return filing deadline. Use the template below to state the statutory requirement clearly.
Vendor workflow to regularize missing IRNs
Suppliers facing this issue must follow the standard IRP registration steps:
- IRP generation: Upload JSON particulars of the invoice to the e-invoice portal (such as einvoice1.gst.gov.in) to generate the 64-character IRN and digitally signed QR code.
- Check cancellation constraints: Per NIC e-Invoice portal guidelines, once an IRN is generated, it cannot be modified. If an IRN was generated and subsequently cancelled, the same invoice number cannot be registered again on the IRP.
- Update return: If the vendor previously filed manual details in GSTR-1, they must reconcile their outward supply tables to reflect the correct e-invoice data.
Frequently asked questions
Can a buyer claim ITC on an invoice without IRN if the supplier is mandated for e-invoicing?
No. Under Rule 48(5) of the CGST Rules, an invoice issued by an applicable supplier without an IRN is not treated as an invoice. Because Section 16(2)(a) requires possession of a valid tax invoice, claiming credit on such an invoice attracts disallowance, demand, and interest under Section 50.
What if an invoice without IRN appears in GSTR-2B?
Even if the vendor manually entered the document in GSTR-1 and it appears in your GSTR-2B, the document fails the tax invoice requirement of Section 16(2)(a) due to Rule 48(5). You should reject or keep it pending in IMS and ask the vendor to generate a valid e-invoice.
Can an IRN be generated for an earlier date if missed?
The supplier can upload the invoice particulars to the Invoice Registration Portal to obtain an IRN. Once generated, an IRN cannot be modified. If cancelled, the same document number cannot be registered again on the IRP per NIC guidelines.
Reconcile your inward supplies safely
Match your purchase register against GSTR-2B records to spot supplier reporting gaps and unauthenticated documents before filing GSTR-3B. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 24 October 2026. Sources: CBIC CGST Rule 48, CBIC CGST Section 16, GSTN GSTR-1 User Manual, NIC e-Invoice System FAQs.