Many business accountants search for GSTR 1 Table 12 HSN summary inward rules when reconciling supplier invoices or facing portal validation errors. Under the Central Goods and Services Tax Rules, Form GSTR-1 is strictly a statement of outward supplies. You do not report inward supplies in Table 12. Instead, inward purchases belong in your purchase register and reconcile against GSTR-2B, while Table 12 demands an exact summary of outward goods and services categorized by Harmonised System of Nomenclature codes.
Mandatory HSN digit thresholds under Notification 78/2020-Central Tax
Reporting requirements in Table 12 depend on your aggregate annual turnover in the preceding financial year. Statutory obligations were notified under Notification No. 78/2020-Central Tax issued under the first proviso to Rule 46 of the CGST Rules:
| Preceding turnover threshold | Minimum HSN digits required | Supply coverage | Statutory mandate |
|---|---|---|---|
| Up to ₹5 crore | 4 digits | Mandatory for B2B; optional for B2C | Notification 78/2020-CT |
| Exceeding ₹5 crore | 6 digits | Mandatory for all B2B and B2C supplies | Notification 78/2020-CT |
According to the official GSTN GSTR-1 FAQ on Table 12, HSN codes must be chosen directly from the portal drop-down list rather than entered as arbitrary free text. Entering an unlisted or truncated 2-digit code will trigger portal validation errors during return upload.
Common mistake: Entering inward supply invoices into Table 12. Inward supplies received under reverse charge or regular trading must never be added to GSTR-1 Table 12. Table 12 reconciles outward liabilities only. To understand how inward supplies flow into your return, check our guide on GSTR-1 Table 9 inward supplies and auto-populated 2B data.
Reconciling Table 12 with outward invoice tables
The primary compliance requirement on the GST portal is ensuring that totals in Table 12 match the cumulative values across all outward tables:
- Table 4: Taxable supplies to registered persons (B2B)
- Table 5: Inter-State supplies to unregistered persons where invoice value exceeds ₹1,00,000 (B2C Large)
- Table 6: Zero-rated supplies and exports
- Table 7: Other intra-State and inter-State supplies to unregistered persons (B2C Others)
- Table 9: Credit notes, debit notes, and historical amendments
Any mismatch between Table 12 taxable value and the sum of Tables 4, 5, 6, and 7 minus Table 9 credit notes generates portal warnings. Persistent variances trigger return scrutiny under Section 61 of the CGST Act, leading to notice issuance in Form GST ASMT-10 under Rule 99 of the CGST Rules.
Unique Quantity Codes and unit alignment
Each HSN line item in Table 12 requires a Unique Quantity Code (UQC). When supplying goods, taxpayers must declare standard units recognised by GSTN, such as:
- BAG: Bags
- BOX: Boxes
- KGS: Kilograms
- MTR: Metres
- NOS: Numbers / Units
- OTH: Others (use only when no prescribed UQC fits)
For service supplies under SAC codes (Chapter 99), quantity and UQC fields are not applicable on the portal, requiring NA selection.
Worked example: Table 12 reconciliation for a manufacturing trader
Consider a registered manufacturer in Pune whose aggregate turnover for the preceding year was ₹3,20,00,000 (up to ₹5 crore threshold). For the current tax period, the business issues B2B invoices and B2CS cash sales across two product lines: industrial fasteners (HSN 7318) and safety helmets (HSN 6506).
The outward sales register for the month shows:
- Fasteners (HSN 7318, 18% GST): 5,000 KGS, Taxable Value = ₹10,00,000, CGST = ₹90,000, SGST = ₹90,000
- Safety helmets (HSN 6506, 18% GST): 1,000 NOS, Taxable Value = ₹5,00,000, IGST = ₹90,000
- Total outward turnover across Tables 4 and 7: Taxable Value = ₹15,00,000, Total Tax = ₹2,70,000
| HSN code | Description | UQC | Total quantity | Total taxable value | Integrated tax | Central tax | State tax |
|---|---|---|---|---|---|---|---|
| 7318 | Screws, bolts, nuts of iron | KGS | 5,000 | ₹10,00,000 | ₹0 | ₹90,000 | ₹90,000 |
| 6506 | Other headgear safety helmets | NOS | 1,000 | ₹5,00,000 | ₹90,000 | ₹0 | ₹0 |
| Total Table 12 | Consolidated | N/A | N/A | ₹15,00,000 | ₹90,000 | ₹90,000 | ₹90,000 |
Formula verification check:
- Total Table 12 Taxable Value = ₹10,00,000 + ₹5,00,000 = ₹15,00,000
- Outward Tables (Table 4 + Table 7) Taxable Value = ₹15,00,000
- Difference = ₹15,00,000 - ₹15,00,000 = ₹0 (Matched)
- Total Tax = ₹90,000 (IGST) + ₹90,000 (CGST) + ₹90,000 (SGST) = ₹2,70,000 (Matched)
Step-by-step checklist to avoid Table 12 discrepancies
- Select valid HSN digits: Use 4 digits if turnover is up to ₹5 crore, or 6 digits if turnover exceeds ₹5 crore.
- Standardize UQC measurement: Match measurement units in your billing software to GSTN prescribed UQC codes.
- Reconcile before filing: Verify that the sum of taxable values across HSN lines equals the total in outward sales tables.
- Exclude inward purchases: Never enter purchases or input tax credit lines in Table 12.
Frequently asked questions
Are inward supplies reported in Table 12 of GSTR-1?
No. Table 12 of Form GSTR-1 captures only the HSN-wise summary of outward supplies. Inward supplies received from suppliers are reflected in your purchase register and auto-populated GSTR-2B, never in Table 12.
How many digits of HSN are mandatory in Table 12?
Under Notification No. 78/2020-Central Tax, businesses with aggregate turnover up to Rs 5 crore must report a minimum of 4 digits for B2B supplies, while businesses with turnover exceeding Rs 5 crore must report a minimum of 6 digits for all supplies.
What causes an HSN mismatch between Table 12 and outward tables?
Discrepancies happen when the net taxable value or tax amounts in Table 12 do not match the cumulative values entered in Table 4 B2B, Table 5 B2CL, Table 6 exports, Table 7 B2CS, and Table 9 credit or debit notes.
Reconcile your inward purchase register with GSTR-2B
While Table 12 covers outward supplies, verifying inward supplier HSN compliance requires matching your purchase register against monthly GSTR-2B data. Our browser reconciliation tool matches invoices, detects missing credits, and highlights rate differences locally without uploading data to external servers.
Your GSTR-2B and purchase register files are read in your browser and never uploaded to any server.
Last checked: 23 October 2026. Sources: Notification No. 78/2020-Central Tax, GSTN GSTR-1 User Manual & FAQs, Rule 59 of CGST Rules.