Compliance Tool / Return Validator

GSTR-1 Table 12 HSN Summary & UQC Format Checker (2026)

Validate GSTR-1 Table 12 HSN summary 4/6-digit rules, fix UQC Unit Quantity Code mapping errors in Tally Prime, and prevent GST portal JSON return upload rejections.

Quick Answer: What Are the GSTR-1 Table 12 HSN & UQC Rules?

GSTR-1 Table 12 requires minimum 4-digit HSN codes (AATO ≤ ₹5 Cr) or 6-digit HSN codes (AATO > ₹5 Cr), split into B2B and B2C tabs. Manual typing is disabled; HSN codes must be selected from the portal dropdown. All units of measurement must be mapped to official GST Unit Quantity Codes (UQCs) like KGS, MTR, NOS in Tally Prime.

  • AATO ≤ ₹5 Cr: 4-digit HSN. AATO > ₹5 Cr: 6-digit HSN. Exports: 8-digit HSN.
  • Table 12 is bifurcated into B2B and B2C tabs on the GST portal.
  • UQC mapping errors in Tally Prime resolved via Display > GST Reports > Map UoM - UQC.
  • Table 12 totals must strictly match total taxable values declared in main GSTR-1 tables.

GSTR-1 Table 12 HSN Digit Threshold Matrix (2026)

Aggregate Turnover (AATO)Min HSN DigitsB2B Tab RequirementB2C Tab Requirement
Up to ₹5 Crore4 DigitsMandatoryOptional
Above ₹5 Crore6 DigitsMandatoryMandatory
Exports / Imports8 DigitsMandatory (Customs Tariff)N/A

How to Fix UQC Unit Mapping Errors in Tally Prime (Step-by-Step)

1
Open Map UoM - UQC Report

Go to Gateway of Tally > Display More Reports > Statutory Reports > GST Reports > Map UoM - UQC.

2
Select Unmapped Unit

Identify units showing unmapped status (e.g. Kgs, Mtr, Box, Nos).

3
Assign Official GST UQC

Click Map to UQC. Select standard GST code from dropdown (e.g. KGS - KILOGRAMS, MTR - METERS, NOS - NUMBERS, OTH - OTHERS).

4
Resolve Uncertain Transactions

Check GSTR-1 report > Uncertain Transactions. Confirm zero unit errors remain before exporting JSON return.

Automate Purchase Invoice Entry with HSN Validation

Post verified vendor bills with valid HSN codes to Tally in 15 seconds.

TrulyInvoice AI extracts 4/6-digit HSN codes and UQC units directly from vendor PDF bills during purchase entry automation, eliminating GSTR-1 Table 12 mismatches and invalid HSN errors in Tally Prime.

Frequently Asked Questions

What are the 2026 HSN code digit requirements for GSTR-1 Table 12?▾
AATO ≤ ₹5 Crore: Minimum 4-digit HSN code required. AATO > ₹5 Crore: Minimum 6-digit HSN code required for all B2B supplies. Export/Import transactions require 8-digit HSN codes.
What is the new B2B vs B2C bifurcation in GSTR-1 Table 12?▾
Under current Phase 3 rules, Table 12 is split into separate B2B and B2C tabs. Reporting HSN summary under the B2B tab is mandatory for all taxpayers with B2B sales. Dropdown selection is required (manual typing disabled).
How to fix 'UoM not mapped to Unit Quantity Code (UQC)' in Tally Prime?▾
Go to Gateway of Tally > Display > GST Reports > Map UoM - UQC. Select unmapped units (e.g. Kgs, Mtr, Nos) and assign official GST UQC codes (e.g. KGS, MTR, NOS). Alternatively, resolve via GSTR-1 > Uncertain Transactions report.
How does TrulyInvoice ensure valid HSN codes in Tally Prime purchase entries?▾
TrulyInvoice AI extracts verified 4/6/8-digit HSN codes directly from vendor PDF bills during purchase entry automation. It auto-creates or maps stock items with valid HSN and UQC parameters in Tally Prime.
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