📅 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.
🎬 Click below to watch the 5-minute summary video
📘 Table of Contents
- Why Everyone Thinks Form 3B Is Automatic—And Why That’s a Mistake
- How Your Books of Accounts Link to Form 3B
- Monthly Reconciliation Tasks Before Filing Form 3B
- Form 3B Section-Wise Explained with Accounting Logic
- Real Case: March 2025 Filing with Logic
- Reverse Case: ITC From Past Invoices Now in 2B
- Why Your Carry Forward Register Must Match Ledger Monthly
- Accounting Entries Under GST (Tally Format)
- 🚨 Latest Changes in Form 3B (Effective July 2025)
- Final Thoughts: Don’t Take Form 3B Lightly
- Frequently Asked Questions
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.
📊 How Your Books of Accounts Link to Form 3B
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–5th | Update Sales Register | Tally / ERP |
| 6th–8th | Prepare GSTR-1 with HSN summary | Excel |
| 9th–11th | Validate purchases & download GSTR-2B | GST Portal |
| 14th–16th | Match ITC Register with 2B | Pivot Table, VLOOKUP, Excel Automation |
| 15th–16th | Prepare RCM & Carry Forward Registers | Manual Ledger |
| 17th–18th | Compute liability & draft Form 3B | GST Portal |
| By 20th | Final preview and file Form 3B | GSTN Portal |
📄 Form 3B Section-Wise Explained with Accounting Logic
1. Section 3.1: Outward & RCM Supplies
| Code | Description |
|---|---|
| (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:
| Action | Journal 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:
| Step | Checkpoint |
|---|---|
| Unmatched invoices | Present in C/F Register |
| Claimed items | Transferred to Input GST |
| Reversed items | Cleared from both sources |
📘 Example Reconciliation:
| Month | C/F Register | C/F Ledger | Remarks |
|---|---|---|---|
| Jan | ₹12,000 | ₹12,000 | 2 invoices unmatched |
| Feb | ₹5,000 | ₹5,000 | 1 claimed, 1 added |
| Mar | ₹0 | ₹0 | All matched & claimed |
🧾 Accounting Entries Under GST (Tally Format)
🔹 Intrastate Purchase @18%
Invoice Value: ₹1,00,000 | GST: ₹9,000 CGST + ₹9,000 SGST
🔹 Intrastate Sale @18%
Sale Value: ₹1,50,000 | GST: ₹13,500 CGST + ₹13,500 SGST
🔹 RCM Entry on Legal Fees @18%
Legal Fees: ₹25,000 | GST: ₹2,250 CGST + ₹2,250 SGST
🔹 Tax Liability Set-off (Using Credit + Cash)
Total Liability: ₹27,000 | ITC Used: ₹20,000 | Paid by Cash: ₹7,000
🔹 Carry Forward ITC Adjustment (Next Month)
Invoice matched in GSTR-2B this month (₹3,150 + ₹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
- HSN-Wise Outward Sales Register Under GST (2025)
- GSTR‑3B & ITC Register Excel Format (Free Download Guide)
- Avoid These 3 Costly GST Filing Mistakes
📥 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!
We do not sell or promote any regulated financial products. Always consult a SEBI-registered advisor before making financial decisions.
👉 Read full disclaimer here.