GSTR-3B Return Filing Guide: Tables, ITC, RCM & Mistakes

Q: How should GSTR-3B be prepared?

Prepare GSTR-3B from approved books and supporting workings, reconcile outward supplies with GSTR-1/1A, reconcile purchase-side ITC with GSTR-2B and applicable IMS information, review RCM and reversals, verify portal auto-population, and complete a final review before payment and filing.

Q: What are common GSTR-3B filing mistakes?

Common control failures include sales errors, omitted RCM, ineligible ITC, missed reversals, wrong tax type or state/POS, duplicate Section 9(5) reporting, and filing without reconciling the final return to the approved working.

1. What is GSTR-3B and how should GSTR-3B return filing be approached?

GSTR-3B is the summary return in which a taxpayer declares the relevant GST liability, eligible ITC, reversals, other required figures and the manner in which the liability is discharged.

The easiest way to understand it is: GSTR-3B is the final summary of your GST position for the tax period. It should not be prepared by simply copying another return or accepting every auto-populated value without review.

If you are searching for GSTR-3B return filing, GSTR-3B table-wise explanation, how to prepare GSTR-3B, GSTR-3B ITC reconciliation or GSTR-3B RCM reporting, this guide brings the main working points together in one place. It connects outward-supply reporting, purchase-side reconciliation, ITC eligibility, reversals, RCM, payment and review controls.

Golden rule: Close the books → reconcile GSTR-1/1A and GSTR-2B as applicable → determine legally eligible ITC → review RCM/reversals → finalise GSTR-3B → pay/offset → file.

For the legal background, use the GST Act — Section Wise Guide.

2. The practical monthly workflow

Close the books. Finalise sales, purchases, expenses, notes, RCM and relevant adjustments.

Reconcile outward supplies. Compare sales register ↔ GSTR-1/1A ↔ proposed 3.1 and 3.2.

Reconcile ITC. Compare Purchase Register ↔ GSTR-2B and applicable IMS information, then apply eligibility/reversal rules.

Prepare RCM working. Identify transactions where the recipient must pay GST and separately track payment and eligible ITC.

Review portal auto-population. Compare system figures with the approved working.

Finalise liability and payment. Review ITC utilisation, cash requirement, interest/late fee and ledgers.

Preview, file and preserve evidence. Save the filed return, payment evidence and final working paper.

3. Documents to prepare before entering GSTR-3B

Working	What to check	Why it matters
Sales register	Taxable, zero-rated, exempt/nil-rated, non-GST, notes, amendments	Prevents turnover and liability differences.
GSTR-1 / GSTR-1A	Final outward supplies and amendments	Supports 3.1 and 3.2.
Purchase Register	GSTIN, invoice number/date, taxable value and tax	Base for ITC reconciliation.
GSTR-2B	Available ITC and RCM-related information	Identifies supplier-reported credits and exceptions.
RCM register	Transaction, taxable value, tax, payment status	Prevents RCM omission.
ITC reversal working	Rule-wise reversals, blocked credit, temporary reversals and reclaims	Prevents excess ITC.
Electronic ledgers	Liability, cash and credit balances	Confirms final discharge.

Use your GSTR-2B reconciliation resources for purchase-side review.

4. Table 3.1 — Outward supplies and RCM

Row	Simple meaning	Typical source	Main control
3.1(a)	Ordinary taxable outward supplies.	Sales register + GSTR-1/1A	Reconcile taxable value and tax.
3.1(b)	Specified outward supplies attracting reverse charge.	Sales/RCM classification	Check applicable provision/notification.
3.1(c)	Nil-rated and exempt outward supplies.	Sales register	Do not mix with non-GST merely because no GST is charged.
3.1(d)	Inward supplies liable to RCM.	RCM register + invoices + portal data	Reconcile taxable value and tax.
3.1(e)	Non-GST outward supplies.	Sales register	Keep classification separate.

Example — 3.1(a)

Example: Taxable domestic sales = ₹1,00,00,000; GST = ₹18,00,000. The proposed 3.1(a) should be supported by the approved sales/GSTR-1 working after applicable amendments and notes.

If ₹90 lakh is entered instead of ₹1 crore: liability may be understated, creating tax short-payment, interest and other exposure depending on the facts and correction.

5. Table 3.1.1 — Section 9(5) supplies

This table covers specified supplies through electronic commerce operators where the tax responsibility is placed on the ECO under the applicable Section 9(5) mechanism.

Row	Practical meaning
3.1.1(i)	ECO reports applicable supplies on which the ECO pays tax.
3.1.1(ii)	Registered person reports specified supplies made through the ECO as required.

Common mistake: Do not blindly add a Section 9(5) supply to 3.1(a) as ordinary forward-charge turnover when it belongs in the separate reporting mechanism.

6. Table 3.2 — Inter-State supplies to specified recipients

Table 3.2 captures specified inter-State outward supplies to categories such as unregistered persons, composition taxable persons and UIN holders, with state/UT-wise details where required.

Category	What to verify
Unregistered persons	Customer status, inter-State nature, POS and taxable value.
Composition taxable persons	Recipient GST status and POS.
UIN holders	UIN details and applicable reporting.

Wrong POS can affect tax type, state-wise reporting and reconciliation.

7. Table 4 — Eligible ITC

Do not calculate Table 4 by adding every purchase invoice. Determine eligible credit first, then apply restrictions, reversals and reclaim rules.

Row	Simple explanation	Practical source/check
4(A)(1)	Import of goods	Bill of Entry and import records.
4(A)(2)	Import of services	Import-of-service/RCM working and eligibility.
4(A)(3)	Inward supplies liable to RCM	RCM register and portal data.
4(A)(4)	ITC received through ISD	ISD documents and recipient records.
4(A)(5)	Other eligible ITC	Purchase Register ↔ GSTR-2B ↔ eligibility review.
4(B)(1)	Reversals required under specified rules	Rule-wise reversal working.
4(B)(2)	Other reversals	Temporary/other applicable reversals with audit trail.
4(C)	Net ITC after applicable reversals	4(A) less 4(B), subject to prescribed structure.
4(D)(1)	Eligible ITC reclaimed after earlier reversal	Link reclaim to original reversal.
4(D)(2)	Specified unavailable/restricted ITC	Review portal value and independent eligibility analysis.

Correct ITC thought process

Purchase Register → GSTR-2B / applicable IMS review → Invoice reconciliation → ITC eligibility → Blocked/restricted credit → Reversal/reclaim → Table 4

Example: Purchase ₹10,00,000 + GST ₹1,80,000. If ₹30,000 is blocked/ineligible, do not claim the full ₹1,80,000 merely because it appears in books or 2B. Apply the relevant eligibility rules first.

Important: A 2B match is a reconciliation control; it does not by itself prove legal eligibility. Use the Input Tax Credit practical guide.

8. Table 5 — Exempt, nil-rated and non-GST inward supplies

This table concerns specified inward supplies. Do not confuse it with outward reporting in 3.1(c) and 3.1(e).

Area	What to review
From composition taxable persons	Identify applicable inward supplies and classify them correctly.
Exempt / nil-rated / non-GST inward supplies	Review purchase and expense records and classify based on the applicable GST treatment.

9. Table 5.1 — Interest and late fee

Treat Table 5.1 as a liability-control section, not merely a number to accept from the portal.

Check	What the accountant should do
Delayed payment	Identify tax period, amount, due date and actual payment date.
Previous-period liability	Keep period-wise liability/payment details for correct interest computation.
Portal interest	Review the system calculation and use recomputation functionality where applicable.
Late fee	Check filing delay and applicable relief before payment.

Do not hide a tax error inside the interest figure. Correct the underlying liability and period first.

10. Table 6.1 — Payment / offset

Finalise liability.

Finalise eligible ITC.

Check credit ledger.

Determine cash requirement.

Offset/pay and file.

Reporting and payment are different: the return declares the summary position; the payment/offset process discharges the liability.

11. Wrong entries and practical impact

Wrong entry	Possible impact	Control
Sales understated	Short-payment exposure, interest and possible demand depending on facts.	Books ↔ GSTR-1/1A ↔ 3.1.
Sales overstated	Excess tax payment and reconciliation issues.	Invoice-level review.
RCM omitted	Tax short-payment and interest exposure.	Monthly RCM register.
Excess ITC claimed	Reversal and possible interest/other consequences depending on facts.	2B + books + eligibility review.
Required reversal missed	Net ITC may be overstated.	Rule-wise reversal checklist.
Wrong IGST/CGST/SGST	Tax-type and return reconciliation problems.	POS and registration review.
Wrong 3.2 state	State-wise reporting/POS mismatch.	Review customer State/POS.
9(5) duplicated	Potential duplicate reporting.	Separate 9(5) check.

12. How to deal with a wrong figure

The correction route depends on what was wrong, whether the return is already filed, which period is affected and whether the error changes liability or ITC.

Situation	Practical approach
Found before filing	Correct working, verify portal values, preview again and file after approval.
Liability understated after filing	Identify affected period, determine additional liability/interest and use the permitted correction/subsequent-return mechanism.
Excess ITC after filing	Identify amount/period, reverse or correct through the applicable mechanism and evaluate interest/other consequences.
Classification error	Correct/reconcile where permitted even if total tax is unchanged.

Do not use a later return as a dumping ground for unexplained differences. Maintain a correction register showing original figure, corrected figure, reason, period and supporting document.

13. Worked practical examples

Example 1 — GSTR-1 and 3B mismatch. Books show taxable sales ₹50 lakh and tax ₹9 lakh; GSTR-1 also shows ₹50 lakh/₹9 lakh, but the proposed 3.1 working shows ₹47 lakh/₹8.46 lakh. Action: identify the ₹3 lakh difference invoice-wise; check notes, amendments and timing before finalising.

Example 2 — Purchase in books but not 2B. Purchase Register has GST ₹1,00,000 but the invoice is absent from relevant 2B. Action: mark as exception, verify supplier reporting and determine legal eligibility for the relevant period rather than treating books alone as automatic ITC approval.

Example 3 — RCM. An inward service is subject to RCM but the expense is recorded without the RCM liability. Risk: liability can be understated; independently review the RCM register.

Example 4 — Reclaim. ₹40,000 was temporarily reversed earlier and later becomes eligible. Control: link the reclaim to the original reversal and keep current eligibility evidence.

14. Internal controls for a professional GSTR-3B process

Control	Responsible activity	Evidence
Sales reconciliation	Accounts prepares Books ↔ GSTR-1/1A ↔ 3B.	Approved reconciliation and exception list.
ITC reconciliation	Accounts reconciles Purchase Register ↔ 2B and follows exceptions.	Invoice-level report and vendor follow-up.
ITC eligibility	Reviewer checks restrictions, blocked credit and reversals.	Eligibility/reversal working.
RCM control	Accounts independently reviews expense ledgers and RCM register.	RCM register, invoices and payment proof.
Return review	Preparer enters; reviewer checks; authorised person files.	Pre-filing checklist and preview.
Payment control	Payment/offset checked against final liability and ledgers.	Challan/payment and ledger reconciliation.
Post-filing	Filed return reconciled to final working.	Filed return/acknowledgement and working papers.

15. Final filing checklist

Books for the period are closed/frozen for return preparation.
GSTR-1/1A is reconciled with sales and proposed 3.1/3.2.
RCM register reviewed independently.
Purchase Register reconciled with GSTR-2B and applicable IMS information.
ITC eligibility and blocked/restricted credit reviewed.
4(A), 4(B), 4(C), 4(D) supported by working.
3.2 state-wise details checked.
Section 9(5) transactions checked where applicable.
Interest/late fee reviewed with correct period.
Auto-populated values compared with approved working.
Final liability, credit ledger and cash requirement agree.
Preview checked before filing.
Filed return, payment evidence and final workings saved.

16. GST legal and practical references

This version intentionally uses GST Reconciliation as the primary reference library rather than sending readers to outside websites for every concept.

Topic	Internal reference	Status
CGST Act section-wise provisions	GST Act — Section Wise Guide	Available
ITC eligibility/restrictions	Input Tax Credit Practical Guide	Available
GSTR-2B reconciliation	GSTR-2B Reconciliation Guide	Available / verify URL
GST compliance workflow	GST Compliance Centre	Available
Rules, notifications and circulars	Dedicated internal legal-reference pages	Needs expansion

Reference pages I recommend adding to your website

Priority	Page	Why this article needs it
1	CGST Act Section 16 — ITC eligibility	ITC conditions and time limits.
2	CGST Act Section 17 — apportionment/blocked ITC	Blocked credit and reversals.
3	CGST Act Section 39 — returns	Core statutory return provision.
4	CGST Act Section 49 — payment/electronic ledgers	Payment and utilisation.
5	CGST Act Section 50 — interest	Interest explanation.
6	CGST Act Section 9(5)	Table 3.1.1.
7	Rule 37 — ITC reversal/reclaim	Reversal/reclaim examples.
8	Rules 38, 42 and 43	Rule-based ITC reversals.
9	Rule 88B — interest calculation	Detailed interest working.
10	Circular 170/02/2022-GST	3.2 and Table 4 reporting guidance.
11	GSTR-3B portal procedure/user guide	Current portal workflow and auto-population.
12	GSTR-2B portal/FAQ reference	2B auto-population and ITC/RCM context.

Recommended website architecture: Article → GST Act Section → Rule → Notification → Circular → Practical example. This will turn your website into a connected GST knowledge base instead of a collection of isolated articles.

Related GST return filing resources

Continue your GST compliance research with the GST Compliance Centre, the GSTR-2B Reconciliation Guide, and the Input Tax Credit Practical Guide. These internal resources are designed to connect the return-filing workflow with the underlying GST working papers.

Quick reference: GSTR-3B in one view

Table	Main question
3.1	What outward liability and inward RCM liability belongs to this period?
3.1.1	Are there specified Section 9(5) ECO supplies?
3.2	What specified inter-State supplies need state-wise reporting?
4	What ITC is genuinely eligible after restrictions/reversals?
5	What relevant exempt/nil-rated/non-GST/composition inward supplies exist?
5.1	Is interest/late fee applicable?
6.1	How will the final liability be discharged?

17. Frequently asked questions about GSTR-3B return filing

What is GSTR-3B?

GSTR-3B is the summary GST return in which the taxpayer reports the relevant GST liability, eligible ITC, reversals, other required figures and the manner in which the liability is discharged.

How should GSTR-3B be prepared?

Prepare the return from approved books and supporting workings. Reconcile outward supplies with GSTR-1/1A, reconcile purchase-side ITC with GSTR-2B and applicable IMS information, review RCM and reversals, verify portal auto-population, and complete a final review before payment and filing.

How do I reconcile GSTR-3B with GSTR-2B?

GSTR-2B is primarily a purchase-side ITC reconciliation input. Compare the Purchase Register with GSTR-2B invoice-wise, investigate missing or mismatched invoices, assess ITC eligibility separately, and then support the relevant Table 4 figures with the approved working.

What is reported in GSTR-3B Table 3.1?

Table 3.1 covers the specified outward-supply and reverse-charge categories. The exact treatment should be determined from the transaction classification and the applicable GST provisions for the relevant tax period.

What is GSTR-3B Table 4?

Table 4 deals with ITC reporting, including eligible ITC, specified reversals and other prescribed ITC disclosures. A match in GSTR-2B is a reconciliation control and does not, by itself, establish legal eligibility.

What are common GSTR-3B filing mistakes?

Common control failures include understating or overstating sales, omitting RCM, claiming ineligible ITC, missing required reversals, using the wrong tax type or state/POS, duplicating Section 9(5) reporting, and filing without reconciling the final return to the approved working.

How can a wrong GSTR-3B figure be corrected?

The appropriate correction depends on the nature of the error, the affected period, whether the return has already been filed and whether liability or ITC changes. Maintain a correction register and use the permitted correction or subsequent-return mechanism applicable to the circumstances.

Disclaimer: This guide is for educational and practical working purposes. GST law, rules, notifications, circulars, advisories, return forms and portal functionality can change. Apply the law and procedure relevant to the specific tax period and transaction.