Holding an invoice copy was once enough to defend an ITC claim during an audit. Today, having physical or digital possession of a tax document is only step one. If the document misses mandatory statutory particulars, or fails to reflect in your auto-generated GSTR-2B statement, tax officers disallow the credit under Rule 36 of the Central Goods and Services Tax Rules, 2017.
The 5 prescribed documents under Rule 36(1)
The law does not accept payment vouchers, purchase orders, delivery challans, or proforma invoices as valid claim vouchers. Rule 36(1) of the CGST Rules explicitly restricts ITC claims to five tax documents:
- Supplier tax invoice: Issued by a registered supplier under Section 31 of the CGST Act for regular domestic inward supplies.
- Self-invoice for reverse charge: Issued by the recipient under Section 31(3)(f), CGST Act when receiving taxable goods or services from an unregistered supplier under Section 9(3) or Section 9(4). Rule 36(1)(b) allows credit on this invoice subject to payment of reverse charge tax.
- Debit note: Issued by the supplier under Section 34 of the CGST Act to increase taxable value or tax previously charged on an earlier invoice.
- Bill of entry: Document prescribed under the Customs Act, 1962, or an assessment order issued for the customs clearance of imported goods.
- ISD invoice or credit note: Issued by an Input Service Distributor under Rule 54(1) of the CGST Rules to distribute common input service credit across related business units.
Common mistake: Claiming reverse charge credit on unregistered purchases without generating a formal self-invoice. Section 31(3)(f) mandates that the recipient issue an invoice on the date of receipt. Without this self-invoice on record, the credit fails Rule 36(1)(b) verification during department scrutiny.
Mandatory particulars required on each document
Rule 36(2) provides that Input Tax Credit shall be availed only if all the applicable particulars specified in Chapter VI (Tax Invoice, Credit and Debit Notes) are contained in the document. However, minor clerical omissions do not automatically invalidate your entire credit.
Under the proviso to Rule 36(2), CGST Rules, if a document does not contain all the detailed statutory particulars, input tax credit may still be availed provided it contains these 5 essential details:
| Essential field | Statutory purpose | Audit risk if omitted |
|---|---|---|
| Amount of tax charged | Establishes exact CGST, SGST, IGST, or Cess paid | Disallowed: tax quantum unverified |
| Description of goods or services | Identifies business eligibility and Section 17(5) block status | Disallowed: nature of supply unknown |
| Total value of supply | Validates taxable base value against tax rate calculation | Disallowed: value mismatch |
| GSTIN of supplier and recipient | Confirms legal identity of buyer and seller | Disallowed: buyer identity unproven |
| Place of supply (inter-State) | Validates whether IGST was legally leviable | Disallowed: wrong head of tax claimed |
Document possession versus GSTR-2B reflection
Having a valid document in your accounting folder satisfies Section 16(2)(a). But document possession alone is no longer sufficient to claim credit in table 4 of FORM GSTR-3B.
With effect from 1 January 2022, Notification No. 40/2021-Central Tax amended Rule 36(4). No credit can be availed in respect of invoices or debit notes unless:
- The supplier has furnished the document details in their statement of outward supplies in FORM GSTR-1 or via the Invoice Furnishing Facility (IFF).
- The details have been communicated to the recipient in FORM GSTR-2B.
The earlier provisional buffer (initially 20%, reduced to 10%, and finally 5% under Notification No. 94/2020-Central Tax) was completely eliminated on 1 January 2022. You can read our detailed guide on input tax credit conditions and GSTR-2B rules to see how section 16(2)(aa) works alongside document checks.
Worked example: checking document validity and GSTR-2B status
Consider an engineering firm, Apex Fabtech LLP, reviewing four inward transactions for a tax period. The firm holds documents for each transaction, but must verify statutory validity under Rule 36 before filing GSTR-3B.
| Document reference | Type of document | Document fields checked | Status in GSTR-2B | ITC eligible in 3B |
|---|---|---|---|---|
| INV-412 | Supplier tax invoice | All 5 core fields present | Appears in GSTR-2B | ₹36,000 (Eligible) |
| DN-88 | Supplier debit note | Missing recipient GSTIN | Appears in GSTR-2B | ₹0 (Defective document) |
| SELF-019 | RCM self-invoice s.31(3)(f) | All particulars complete | Not applicable (RCM inward) | ₹12,000 (Eligible after tax paid) |
| INV-504 | Supplier tax invoice | Valid invoice in hand | Not uploaded by vendor | ₹0 (Blocked by Rule 36(4)) |
Formula for eligible ITC in GSTR-3B:
Total book ITC recorded: ₹36,000 + ₹5,400 + ₹12,000 + ₹18,000 = ₹71,400.
Disallowed ITC: ₹5,400 (DN-88 fails Rule 36(2) recipient identification) + ₹18,000 (INV-504 missing from GSTR-2B under Rule 36(4)) = ₹23,400.
Net eligible ITC for the month: ₹71,400 - ₹23,400 = ₹48,000.
Frequently asked questions
Can you claim ITC if an invoice misses the supplier address?
Yes, under the proviso to Rule 36(2) of the CGST Rules, ITC may still be availed if the document contains at least five key particulars: the amount of tax charged, description of goods or services, total value of supply, GSTIN of the supplier and recipient, and place of supply for inter-State supplies.
Is a self-invoice mandatory for reverse charge credit from unregistered suppliers?
Yes. Under Section 31(3)(f) and Rule 36(1)(b) of the CGST Rules, a registered person liable to pay tax under reverse charge on supplies from an unregistered person must issue an invoice. Subject to payment of tax, that self-invoice serves as the legal document to claim ITC.
Can you claim credit solely based on a tax invoice in hand?
No. Having a physical tax invoice is only one condition under Section 16(2)(a). Under Section 16(2)(aa) and Rule 36(4), the invoice details must also be furnished by the supplier in GSTR-1 or the IFF and communicated to you in FORM GSTR-2B.
Check your own GSTR-2B
Verify that every inward tax invoice and debit note in your purchase register actually appears in your GSTR-2B before filing GSTR-3B. Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 26 October 2026. Sources: CBIC CGST Rule 36, Notification No. 40/2021-Central Tax.