GST Law, Returns, GSTR-1, GSTR-3B & TDS
A comprehensive fictional compliance-reporting sample showing the workflow from source transactions to GST returns, ITC reconciliation, tax payment, TDS deduction and quarterly TDS reporting.
1. GST Law — What the Reporting Process Is Based On
A practical GST workflow should begin with the underlying law and applicable rules, not with the return form alone. Key areas include taxable supply, registration, tax invoice, time and place of supply, value of supply, tax payment, input tax credit, reverse charge, returns, refunds and compliance controls.
2. GST Returns & Statements — Practical Map
| Form | Purpose | Portfolio Example |
|---|---|---|
| GSTR-1 | Outward supply details / sales reporting | B2B, B2C, exports, notes, HSN/SAC |
| GSTR-1A | Optional amendment/addition facility for the same period before GSTR-3B | Correct missed or incorrect records |
| GSTR-2B | Static ITC statement generated from supplier/other source data | Reconcile eligible ITC before GSTR-3B |
| GSTR-3B | Summary return for outward supplies, tax liability, ITC and payment | Calculate net tax payable |
GSTR-1 Filing Timing
The GST Portal's GSTR-1 guidance states that the normal due date is the 11th of the succeeding month for monthly filers and the 13th of the month following the quarter for quarterly filers, subject to extensions by notification.
3. GSTR-1 — Outward Supply Reporting
GSTR-1 is the statement used to report outward supplies. The GST Portal describes B2B supplies, B2C supplies, exports, credit/debit notes, advances, amendments, nil/exempt/non-GST supplies and HSN/SAC summaries among the reported information.
| Example Transaction | Taxable Value | GST | GSTR-1 Treatment |
|---|---|---|---|
| B2B Inter-State Sale | ₹1,00,000 | IGST ₹18,000 | B2B invoice reporting |
| B2C Intra-State Sale | ₹50,000 | CGST ₹4,500 + SGST ₹4,500 | B2C summary reporting |
| Export on Payment of Tax | ₹2,00,000 | Illustrative IGST ₹36,000 | Export invoice reporting |
| Credit Note | -₹10,000 | Illustrative tax adjustment | Credit note reporting |
From May 2025 onwards, the GST Portal says the HSN-wise summary in GSTR-1 is presented separately for B2B and B2C supplies.
4. GSTR-1 — Full Example
| Invoice | Customer Type | Place of Supply | Taxable Value | Tax |
|---|---|---|---|---|
| INV-1001 | B2B | Karnataka | ₹1,00,000 | IGST ₹18,000 |
| INV-1002 | B2B | Tamil Nadu | ₹80,000 | CGST ₹7,200 + SGST ₹7,200 |
| INV-1003 | B2C | Tamil Nadu | ₹50,000 | CGST ₹4,500 + SGST ₹4,500 |
5. GSTR-1A — Example Correction Workflow
GSTR-1A is an optional facility for correcting or adding records for the same tax period. The GST Portal states that it can be used after GSTR-1 or its due date, whichever is later, and before filing GSTR-3B for that period.
6. GSTR-2B — ITC Reconciliation
GSTR-2B is a static ITC statement. The GST Portal advises taxpayers to reconcile GSTR-2B with their books and ensure that ITC is not claimed twice, required reversals are made, and reverse-charge tax is paid where applicable.
Example Reconciliation
7. GSTR-3B — Summary Return & Tax Payment
GSTR-3B is a summary return. The GST Portal currently documents system auto-drafting from GSTR-1/1A and GSTR-2B for relevant liability and ITC sections, while the taxpayer remains responsible for reviewing and filing the correct values.
| GSTR-3B Area | What It Represents | Sample Amount |
|---|---|---|
| 3.1(a) | Taxable outward supplies other than zero-rated supplies | ₹1,00,000 taxable value |
| 3.1(d) | Inward supplies liable to reverse charge | ₹20,000 taxable value |
| 4(A) | Eligible ITC categories | ₹7,500 |
| 4(B) | ITC reversals | ₹500 |
| 4(C) | Net ITC | ₹7,000 |
| 5.1 | Interest / late fee where applicable | ₹0 in this sample |
8. GSTR-3B — Simplified Tax Calculation Example
The following is a simplified illustration using one IGST liability and eligible ITC. Actual offset depends on the tax heads, ledgers and applicable utilization rules.
9. GST Monthly Control Checklist
- Sales register reconciled with books.
- B2B invoices checked for GSTIN and invoice data.
- B2C and export transactions classified correctly.
- Credit notes and debit notes reviewed.
- GSTR-1 totals reconciled with books.
- GSTR-2B reconciled with purchase records.
- Eligible and ineligible ITC reviewed.
- Reverse-charge liabilities reviewed.
- GSTR-3B values checked against GSTR-1/1A, GSTR-2B and the books before filing.
- Tax payment / cash ledger requirement reviewed.
10. TDS — Current 2026 Framework
For transactions on or after 1 April 2026, TDS obligations are governed by the Income-tax Act, 2025. The Income Tax Department states that the earlier TDS provisions of the Income-tax Act, 1961 were consolidated mainly under sections 392 (salary) and 393 (other specified payments).
For the transition around 31 March / 1 April 2026, the applicable Act depends on the earlier of the credit or payment event.
11. TDS — Contractor / Professional Example
Use the applicable statutory rate and threshold for the exact transaction. The calculation below uses a clearly labelled illustrative rate so that the arithmetic can be understood without treating the example rate as a legal rate.
| Particular | Illustrative Value |
|---|---|
| Professional / Contractor Bill | ₹50,000 |
| Illustrative TDS Rate | 10% |
| Illustrative TDS | ₹5,000 |
| Illustrative Net Payment | ₹45,000 |
12. TDS Compliance Workflow
TDS Statement Examples
| Current Form | Earlier Form Reference | Illustrative Use |
|---|---|---|
| Form 138 | Earlier Form 24Q | Salary TDS statement |
| Form 140 | Earlier Form 26Q | Non-salary resident TDS statement |
| Form 144 | Earlier Form 27Q | Non-resident TDS statement |
| Form 141 | Earlier 26QB / 26QC / 26QD / 26QE use cases | Specified challan-cum-statement cases under section 393(1) |
13. Quarterly TDS Reporting Example
| Month | Payment | TDS Base | Illustrative TDS |
|---|---|---|---|
| April | ₹50,000 | ₹50,000 | ₹5,000 |
| May | ₹40,000 | ₹40,000 | ₹4,000 |
| June | ₹60,000 | ₹60,000 | ₹6,000 |
| Q1 Total | ₹1,50,000 | ₹1,50,000 | ₹15,000 |
The values above use the same illustrative 10% rate solely to demonstrate the reporting arithmetic. The actual rate, threshold and applicability must be checked against the transaction and the law in force for that tax year.
14. Combined GST + TDS Management Dashboard
- GST outward supply data reconciled before filing.
- GSTR-2B reviewed before claiming eligible ITC.
- GSTR-3B liability checked against the reporting records.
- TDS deduction register reconciled with ledger payments.
- Challans and quarterly TDS statements checked for completeness.
15. Official Reference Sources
This portfolio page is based on current official government guidance reviewed for the 2026 reporting environment.
Income Tax Department — TDS Compliance
Accounting, GST & TDS Reporting
This portfolio sample demonstrates a structured way to organize accounting, GST and TDS information into understandable reporting outputs. Actual compliance should always use current law, applicable notifications, authorized records and professional review.
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