Form 3B Filing Is Not Automatic: The Accountant's Guide to Reconciliation, Registers, and Real Risk

📅 Published on: 25 June 2025   |   🌀 Last Updated: 16 July 2025

✍️ Author: Amrut Chitragar


📌 This post is for educational purposes only. Always consult a SEBI-registered advisor before making financial decisions.

📎 Full disclaimer here

TL;DR: Form 3B is a manual GST return—not auto-populated. Errors in ITC, RCM, or register mismatches can cause penalties. This article explains monthly reconciliation, journal entries, and how to safely file 3B with books alignment.
📺 Watch This First: Understand why Form 3B is NOT automatic!
🎬 Click below to watch the 5-minute summary video

Why Everyone Thinks Form 3B Is Automatic—And Why That’s a Mistake

To many, Form 3B feels like an automated return. Upload sales in GSTR-1, pull ITC from GSTR-2B, and the GST portal does the rest. Right?

Wrong.

As any seasoned accountant will tell you, Form 3B is a fully manual return, and any mistake—wrong ITC claim, unmatched invoices, incorrect set-off—can land you a difference notice, interest penalties, or ITC reversal.

It’s not enough to rely on Tally or Zoho Books. Those tools are only as accurate as the data you feed them.

Let’s break down the real workflow, monthly logic, and registers that you must maintain to file Form 3B safely and compliantly.

Every figure in Form 3B must reconcile back to your ledgers, including:

  • Sales Register
  • Purchase Register
  • ITC, RCM & Carry Forward (C/F) Registers
  • Credit & Cash Ledgers

If your 3B shows ₹2,10,000 in ITC, your books should justify this figure with invoice-wise reconciliation, matched to GSTR-2B.

🗓️ Monthly Reconciliation Tasks Before Filing Form 3B

Date Range Task Tool/Method
1st–5thUpdate Sales RegisterTally / ERP
6th–8thPrepare GSTR-1 with HSN summaryExcel
9th–11thValidate purchases & download GSTR-2BGST Portal
14th–16thMatch ITC Register with 2BPivot Table, VLOOKUP, Excel Automation
15th–16thPrepare RCM & Carry Forward RegistersManual Ledger
17th–18thCompute liability & draft Form 3BGST Portal
By 20thFinal preview and file Form 3BGSTN Portal

📄 Form 3B Section-Wise Explained with Accounting Logic

1. Section 3.1: Outward & RCM Supplies

CodeDescription
(a)Taxable domestic sales (non-exempt)
(b)Zero-rated: Exports & SEZ with LUT
(d)Inward supplies under RCM (e.g., legal fees)

2. Section 3.2: Inter-State B2C Supplies

Declare interstate B2C sales by state—used to track IGST split and e-commerce rules.

3. Section 4: Eligible Input Tax Credit (ITC)

Claim only when matched with 2B. Examples:

  • Supplier invoices: Raw material purchases
  • Imports: IGST on goods or services
  • RCM: Pay now, claim next month

4. Section 5: ITC Reversal

Reverse ITC if:

  • Used for exempt supplies
  • Used for personal/non-business purposes
  • Claimed by mistake

5. Section 6.1: Tax Payment

Manually set off your liability:

  • Use credit ledger first
  • Pay rest from cash ledger

6.2: TDS/TCS Credits

Applicable if deducted by e-commerce portals or government buyers.

🧾 Real Case: March 2025 Filing with Logic

Data:

  • Sales (GSTR-1): ₹25,00,000
  • ITC (Books): ₹2,10,000
  • GSTR-2B: ₹2,00,000
  • RCM: ₹12,000
  • Mismatch: ₹10,000 → Move to Carry Forward Register

Entries:

  • Current ITC claim: ₹2,00,000
  • RCM liability to pay: ₹12,000
  • Tax Payment: Offset via Credit + Cash

🔁 Reverse Case: ITC From Past Invoices Now in 2B

If a past purchase now appears in GSTR-2B:

ActionJournal Entry
Claim deferred ITC Debit: Input GST
Credit: C/F Register
Adjust register Remove invoice from Carry Forward register

This confirms eligibility and closes the deferred entry loop.

✅ Why Your Carry Forward Register Must Match Ledger Monthly

To stay audit-ready and prevent mismatches:

StepCheckpoint
Unmatched invoicesPresent in C/F Register
Claimed itemsTransferred to Input GST
Reversed itemsCleared from both sources

📘 Example Reconciliation:

MonthC/F RegisterC/F LedgerRemarks
Jan₹12,000₹12,0002 invoices unmatched
Feb₹5,000₹5,0001 claimed, 1 added
Mar₹0₹0All matched & claimed

🧾 Accounting Entries Under GST (Tally Format)

🔹 Intrastate Purchase @18%

Invoice Value: ₹1,00,000 | GST: ₹9,000 CGST + ₹9,000 SGST

Purchase A/cDr ₹1,00,000
Input CGST A/cDr ₹9,000
Input SGST A/cDr ₹9,000
To Creditor / Bank ₹1,18,000

🔹 Intrastate Sale @18%

Sale Value: ₹1,50,000 | GST: ₹13,500 CGST + ₹13,500 SGST

Debtors / Bank A/cDr ₹1,77,000
To Sales A/c ₹1,50,000
To Output CGST A/c ₹13,500
To Output SGST A/c ₹13,500

🔹 RCM Entry on Legal Fees @18%

Legal Fees: ₹25,000 | GST: ₹2,250 CGST + ₹2,250 SGST

Legal Fees A/cDr ₹25,000
Input CGST A/cDr ₹2,250
Input SGST A/cDr ₹2,250
To Bank A/c ₹29,500

🔹 Tax Liability Set-off (Using Credit + Cash)

Total Liability: ₹27,000 | ITC Used: ₹20,000 | Paid by Cash: ₹7,000

Output CGST A/cDr ₹13,500
Output SGST A/cDr ₹13,500
To Input CGST A/c ₹10,000
To Input SGST A/c ₹10,000
To Bank A/c ₹7,000

🔹 Carry Forward ITC Adjustment (Next Month)

Invoice matched in GSTR-2B this month (₹3,150 + ₹3,150)

Input CGST A/cDr ₹3,150
Input SGST A/cDr ₹3,150
To CGST Input C/F A/c ₹3,150
To SGST Input C/F A/c ₹3,150

💬 Have questions or want to share your experience?
Scroll down and leave a comment — I read and reply to every one!

❓ Frequently Asked Questions

Q1. What is Form GSTR‑3B?
Form GSTR‑3B is a simplified monthly GST return where you self-declare outward supply, eligible ITC, and net tax liability.
Q2. Can GSTR‑3B be revised?
No. Revisions must be done in the next return cycle.
Q3. What if GSTR‑2B and books don’t match?
Hold the ITC and record it in your carry forward register. Claim later when it appears in 2B.
Q4. How do I record RCM in GSTR‑3B?
Declare under 3.1(d) and claim ITC under 4(A)(3) next month if eligible.
Q5. What is the biggest risk in Form 3B?
Claiming mismatched ITC, incorrect tax set-off, or skipping ITC reversals.

🚨 Latest Changes in Form 3B (Effective July 2025)

📢 GSTN Advisory (07 June 2025)

Starting from the July 2025 tax period (returns filed in August 2025), Form GSTR‑3B will auto-fill tax liabilities from GSTR‑1 and these values will be non-editable in the 3B form — all adjustments must now be done via GSTR‑1A.

  • 🔁 No direct edits allowed in GSTR‑3B post‑July.
  • 📅 Late ITC corrections (after 14th) may get deferred to the next month's return.
  • 📊 Accuracy in your GSTR‑1 is now mandatory—no late fixes via 3B.

⛔ Overdue Return Filing Cut-Off (Effective 1 July 2025)

The GST portal will no longer accept returns overdue by more than 3 years. Taxpayers must file pending returns (up to July 2022) before this date.

✅ Action Checklist for Accountants & Businesses:

  • ✔️ Prioritize corrections in GSTR‑1 using GSTR‑1A before the 14th.
  • ✔️ Reconcile GSTR‑2B early to avoid missed ITC.
  • ✔️ File any returns due up to June 2022 by 1 July 2025 or lose filing rights.
  • ✔️ Adjust internal workflows to prepare for locked 3B filings.

📚 Sources: Times of India; Economic Times

🧠 Final Thoughts: Don’t Take Form 3B Lightly

Form 3B is not just a tax form—it’s a monthly financial statement to the GST department.

  • Reconcile ITC with GSTR-2B using Excel tools
  • Maintain C/F, RCM, and ITC registers properly
  • Ensure your 3B return ties back to ledger books
  • Always verify set-off logic and register balances

📚 Related Guides You Must Read

📥 Want a ready-made Excel Register Pack?
✔️ ITC Register
✔️ Carry Forward (C/F) Tracker
✔️ RCM Register
💻 Need automation tools in Excel? Contact me via the Contact Form — I’ll be happy to help!

📌 This article is for educational purposes only.
We do not sell or promote any regulated financial products. Always consult a SEBI-registered advisor before making financial decisions.

👉 Read full disclaimer here.

Post a Comment

Previous Post Next Post