GSTR-3B Summary Return Filing FY 2025-26 — Due Dates, Tables, ITC Auto-Population + Common Errors

Why GSTR-3B matters for Indian SMEs

In the Indian GST framework, GSTR-3B is the consolidated monthly (or quarterly) summary return through which a regular taxpayer declares net tax liability and pays the tax due. It sits at the cash-flow chokepoint of GST compliance — without it, the taxpayer cannot move money to the government, and after sustained non-filing the portal blocks further filings + e-way bill generation + ITC flow.

Over the past several years the GST Network (GSTN) has progressively tightened the GSTR-3B mechanics — most consequentially by locking ITC eligibility to GSTR-2B (the supplier-fed auto-statement) under Section 16(2)(aa) + Rule 36(4). The days of manually estimating ITC are gone; in FY 2025-26, every rupee of claimed ITC must trace to a supplier-uploaded invoice that appears in the taxpayer’s GSTR-2B.

For SMEs, mastering the GSTR-3B mechanics — table structure, auto-population, ledger sequence, late-fee and interest exposure, and the supplier-reconciliation discipline that drives clean filing — is the highest-leverage compliance investment. For the broader GST framework context, see the GST overview pillar.

What GSTR-3B is — the basics

GSTR-3B is a consolidated summary return covering:

• Total taxable outward supplies (sales) — table 3.1
• Inter-state supplies to unregistered / composition / UIN holders — table 3.2 (a breakdown of part of 3.1)
• Inward supplies attracting reverse charge — included in table 3.1(d)
• Eligible Input Tax Credit on inward supplies — table 4
• Exempt + nil-rated + non-GST inward supplies — table 5
• Payment of tax (final liability set-off against credit + cash ledgers) — table 6.1

GSTR-3B is the tax-payment trigger — the taxpayer cannot file the return until the electronic cash ledger and credit ledger collectively cover the declared tax liability.

Who files GSTR-3B

Every regular GST taxpayer is required to file GSTR-3B. The distinction from GSTR-1:

• GSTR-1 is the invoice-level statement of outward supplies (every B2B invoice, every B2C-Large invoice, exports, credit/debit notes). Filed monthly or quarterly (QRMP). Feeds the buyer’s GSTR-2B.
• GSTR-3B is the consolidated summary covering outward supplies + ITC + RCM + tax payment. Filed monthly or quarterly (QRMP).

Both returns are independent compliance obligations; the GSTR-1 totals should reconcile to GSTR-3B Table 3.1, and divergence between the two is a frequently observed source of departmental notice.

Not required to file GSTR-3B:

• Composition Scheme dealers — file CMP-08 quarterly + GSTR-4 annually instead (see Composition Scheme Eligibility)
• Input Service Distributors (ISD) — file GSTR-6 instead
• Non-Resident Taxable Persons (NRTPs) — file GSTR-5
• OIDAR service providers — file GSTR-5A
• Tax deductors under Section 51 — file GSTR-7

Monthly vs Quarterly (QRMP) — frequency

The filing frequency depends on the taxpayer’s aggregate turnover in the preceding FY:

• Aggregate turnover > ₹5 crore in PY OR opted out of QRMP → monthly GSTR-3B
• Aggregate turnover ≤ ₹5 crore in PY + opted into QRMP → quarterly GSTR-3B + monthly tax payment via PMT-06

QRMP mechanics

The QRMP scheme (Quarterly Return Monthly Payment), notified by Notification 82/2020-Central Tax, allows small taxpayers to file the GSTR-3B return quarterly while continuing to pay tax monthly:

• Months 1 and 2 of the quarter — pay tax via Form GST PMT-06 by the 25th of the following month. Two payment approaches are allowed:
  • Fixed Sum Method (FSM) — 35% of the cash paid in the corresponding month of the preceding quarter (auto-calculated by the portal)
  • Self-Assessment Method (SAM) — taxpayer computes actual tax due based on month’s outward and inward supplies
• Month 3 of the quarter — file consolidated quarterly GSTR-3B covering all 3 months. Tax due for M3 + adjustments to M1/M2 cash paid are squared up here.

QRMP is opted-into / opted-out-of on the GST portal at the start of each quarter (or annually for stability). The choice is per GSTIN per state.

Due dates FY 2025-26

Monthly filers

GSTR-3B due by the 20th of the following month:

Tax period	Due date
April 2025	20 May 2025
May 2025	20 June 2025
Each subsequent month	20th of next month

QRMP filers — quarterly GSTR-3B

Staggered by state group:

• Group A (22nd of month after quarter): Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra, Karnataka, Goa, Kerala, Tamil Nadu, Telangana, Andhra Pradesh, Dadra & Nagar Haveli + Daman & Diu, Puducherry, Andaman & Nicobar Islands, Lakshadweep
• Group B (24th of month after quarter): Himachal Pradesh, Punjab, Uttarakhand, Haryana, Rajasthan, Uttar Pradesh, Bihar, Sikkim, Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Meghalaya, Assam, West Bengal, Jharkhand, Odisha, Jammu & Kashmir, Ladakh, Chandigarh, Delhi

QRMP filers — monthly PMT-06 tax payment

• M1 and M2 — PMT-06 challan by the 25th of the following month
• M3 — paid via quarterly GSTR-3B by the 22nd / 24th group date

For end-to-end management of overlapping deadlines, see the GST Return Filing service.

GSTR-3B tables — what gets reported

Table 3.1 — Outward + RCM supplies (auto-populated from GSTR-1)

• 3.1(a): Outward taxable supplies (other than zero-rated, nil-rated, exempted)
• 3.1(b): Outward taxable supplies — zero-rated (exports + supplies to SEZ)
• 3.1(c): Outward supplies — nil-rated, exempted
• 3.1(d): Inward supplies (liable to reverse charge) — this is where the recipient declares RCM-payable amounts. Covers GTA services, services from unregistered suppliers in notified categories, etc. See Reverse Charge Mechanism (RCM).
• 3.1(e): Non-GST outward supplies (alcohol, petroleum products outside GST scope)

Table 3.2 — Inter-state supplies to unregistered / composition / UIN

A supplementary breakdown of the inter-state portion of 3.1(a) that went to unregistered persons, composition dealers, and UIN holders (foreign diplomatic missions, etc.). State-wise split.

Table 4 — Eligible ITC (auto-populated from GSTR-2B)

• 4(A): ITC available — split into (1) Import of goods, (2) Import of services, (3) Inward supplies liable to RCM, (4) Inward supplies from ISD, (5) All other ITC (the bulk — domestic B2B purchases)
• 4(B): ITC reversed — split into reversal under Rules 38 / 42 / 43 / 50CCD, reversal under Section 16(2) second proviso (180-day rule), other reversals
• 4(C): Net ITC available = 4(A) − 4(B)
• 4(D): Ineligible ITC under Section 17(5) blocked credits + others — disclosed but not added to credit ledger

For ITC eligibility mechanics in detail, see the ITC Rules guide.

Table 5 — Exempt + nil-rated + non-GST inward supplies

Values only (no tax). Disclosed for reporting completeness.

Table 6 — Payment of tax

Shows tax liability under each head (IGST, CGST, SGST, Cess) and the offset between tax payable via credit ledger and via cash ledger. The portal enforces the Section 49(5) set-off sequence.

Table 6.1 — Interest + late fee

Interest under Section 50(1) on delayed cash payment of tax. Late fee under Section 47.

ITC auto-population from GSTR-2B

GSTR-2B is the static, auto-drafted ITC statement generated on the 14th of every month for the preceding tax period. It aggregates all invoices uploaded by the taxpayer’s suppliers in their respective GSTR-1s up to the 13th. Static means it does not change after generation — even if a supplier subsequently uploads an invoice for the same period, that invoice appears in the NEXT month’s GSTR-2B, not in the already-generated one.

Section 16(2)(aa) + Rule 36(4) make GSTR-2B the legal floor for ITC eligibility: the taxpayer is only entitled to claim ITC to the extent the invoice appears in GSTR-2B. The portal auto-populates Table 4 of GSTR-3B from the relevant GSTR-2B.

Manual upward overrides are flagged. If the taxpayer manually edits Table 4 to claim ITC on an invoice not in GSTR-2B, the portal highlights the cell in red and surfaces a warning. This is a frequent trigger for Form ASMT-10 scrutiny notices.

The compliant path for missing supplier uploads: push the supplier to upload the missing invoice in their next GSTR-1. The invoice will then appear in the FOLLOWING month’s GSTR-2B, and the taxpayer can claim the ITC in that subsequent GSTR-3B. This shifts the cash-flow timing but preserves the legal eligibility.

For the operational reconciliation workflow, see the GST Reconciliation service.

Tax payment + cash ledger + credit ledger

Three electronic ledgers on the GST portal:

• Electronic Liability Register (PMT-01) — records total tax, interest, late fee, and penalty dues
• Electronic Credit Ledger (PMT-02) — accumulated ITC available for offset against output tax
• Electronic Cash Ledger (PMT-05) — digital wallet funded by bank challan (ITNS / PMT-06). Used for tax dues not offsetable by ITC + all interest + late fee + penalty + RCM tax

Set-off sequence (Section 49(5))

Strict order enforced by the portal:

1. IGST credit can offset IGST first, then CGST, then SGST (in that order)
2. CGST credit can offset CGST, then IGST. Cannot offset SGST.
3. SGST credit can offset SGST, then IGST. Cannot offset CGST.
4. Cess credit can only offset Cess liability.

Cross-utilisation between CGST and SGST is not allowed in either direction. This is a frequent source of cash-flow surprises where one head shows surplus credit while another head shows a cash payment requirement.

Late filing + interest consequences

• Late fee (Section 47) — ₹50/day (₹25 CGST + ₹25 SGST) for normal returns; ₹20/day for Nil returns. Capped at ₹5,000 per Act per return for standard taxpayers (lower caps for some categories per various notifications).
• Interest on delayed tax (Section 50(1)) — 18% per annum on the cash component of tax paid late (interest is not levied on the portion offset by ITC).
• Interest on wrongful excess ITC (Section 50(3)) — 24% per annum on excess ITC that was actually utilised to offset tax. Note: this applies only where the ITC was both wrongly claimed AND utilised; mere claim without utilisation typically attracts the 18% rate.
• GSTIN suspension (Rule 21A) — continuous non-filing of GSTR-3B for 6 months (or 2 quarters for QRMP filers) triggers suo motu suspension of the GSTIN. E-way bill generation is also blocked after 2 months of non-filing under Rule 138E.

Common GSTR-3B errors

1. GSTR-1 vs GSTR-3B mismatch on Table 3.1 — declaring different totals in GSTR-1 (invoice-level) and GSTR-3B (summary). The portal compares the two and surfaces discrepancies; sustained mismatch can trigger Section 79 recovery proceedings on the under-declared tax.
2. Claiming ITC not in GSTR-2B — manually overriding Table 4 to claim ITC against invoices not auto-populated. Triggers ASMT-10 scrutiny + interest exposure under Section 50(3).
3. Missing 180-day reversal — Section 16(2) proviso requires reversal of ITC where the supplier has not been paid within 180 days from invoice date. Reversal flows into Table 4(B) of the GSTR-3B following the 180-day breach. ITC can be re-claimed once payment is made.
4. Incorrect RCM reporting — RCM tax must be declared in Table 3.1(d) AND paid via cash ledger (cannot be paid via credit), AND the corresponding ITC (where eligible) can be claimed in Table 4(A)(3) of the same return. Forgetting the simultaneous credit creates a cash drag.
5. Wrong place-of-supply (POS) in Table 3.2 — selecting wrong state code splits IGST vs CGST/SGST incorrectly. Affects inter-state revenue distribution; cross-tax-period adjustments are operationally complex.
6. 30 November cut-off violation — Section 16(4) requires ITC pertaining to a FY to be claimed by 30 November of the following FY (or the date of filing the annual return for that FY, whichever is earlier). Claiming prior-FY ITC after this cut-off is disallowed at processing.
7. Common-credit ITC reversal missed under Rules 42 / 43 — taxpayers with mixed supplies (taxable + exempt) must reverse ITC attributable to the exempt portion using the prescribed formula. Frequently missed for first-time mixed-supply taxpayers.
8. Cash payment when credit ledger has balance — paying tax via cash ledger when credit is available wastes working capital. Always exhaust credit first (subject to the Section 49(5) sequence).

For annual reconciliation across all monthly GSTR-3Bs + GSTR-1s + the books, see the GSTR-9 Annual Return service.