GSTR-1 and GSTR-3B at a glance
| Point | GSTR-1 | GSTR-3B |
|---|---|---|
| Primary purpose | Report outward supply details | Declare summary liability, ITC and tax payment |
| Level of detail | Invoice and consolidated supply details | Consolidated tax-period summary |
| Tax payment | Normally not discharged through this form | Liability is discharged while filing |
| Key control | Completeness of sales reporting | Accuracy of liability and eligible ITC |
What is GSTR-1?
GSTR-1 captures details of outward supplies for the tax period. It is a major source of supplier-reported invoice information in the GST ecosystem and should agree with sales registers, credit notes, debit notes and other relevant records.
- B2B invoice details and amendments.
- Applicable B2C, export and other outward-supply information.
- Credit and debit notes.
- Advances and adjustments where relevant.
What is GSTR-3B?
GSTR-3B is a simplified summary return in which taxpayers declare summary GST liabilities for a tax period and discharge those liabilities. It also contains sections for eligible input tax credit and other prescribed information.
Why reconciliation matters
Differences between sales books, GSTR-1 and GSTR-3B can create incorrect liability, customer credit issues and audit risk. A monthly reconciliation makes corrections easier and produces a clear trail.
- Lock the sales register for the period.
- Map invoices, notes and amendments to GSTR-1.
- Compare taxable value and tax by rate and place of supply.
- Review GSTR-3B liability against the final outward-supply summary.
- Document differences and approved adjustments.
Common causes of mismatch
- Invoice reported in the wrong tax period.
- Credit note recorded in books but omitted from the return.
- Incorrect GSTIN, place of supply or tax rate.
- Amendment made in one record but not the other.
- Rounding or classification differences.
A practical monthly control
Maintain a return working paper that links the sales register, GSTR-1 summary, GSTR-3B liability and tax payment. The reviewer should sign off material differences before filing.
Explore our professional GST Returns & Compliance service for practical support tailored to your business.
