GSTR-1 is the detailed statement of your outward supplies (sales), invoice by invoice. GSTR-3B is the summary return where you report total tax liability and eligible input tax credit and pay the tax. Customers' input credit depends on GSTR-1, while your payment is made through GSTR-3B.
The short comparison
| GSTR-1 | GSTR-3B | |
|---|---|---|
| What it is | Details of outward supplies | Summary return with tax payment |
| Level of detail | Invoice-wise and document-wise | Consolidated totals |
| Key purpose | Feeds your customers' GSTR-2B so they can claim credit | Declares liability, claims your ITC and pays tax |
| Includes tax payment? | No | Yes |
| Why mismatches arise | Wrong invoice data, missed invoices, amendments | Different totals from GSTR-1, ITC claimed beyond GSTR-2B |
How they connect
What you report in GSTR-1 flows into your customer's GSTR-2B. What you report and pay in GSTR-3B settles your own liability. If the two returns tell different stories about your sales, the department notices, so the totals need to reconcile every month.
A simple monthly routine
- ✓Close sales entries for the period and review for missing or duplicate invoices.
- ✓Prepare and file GSTR-1 from the books, and check amendments and credit notes.
- ✓Reconcile purchases with GSTR-2B and decide what ITC is eligible.
- ✓Prepare GSTR-3B from the same books, compare its sales totals with GSTR-1, and pay.
- ✓Keep a short reconciliation note for each month in case of a notice.
Common mistakes
- ✓Filing GSTR-3B from memory or a spreadsheet that does not tie to the books.
- ✓Claiming ITC for invoices that have not appeared in GSTR-2B.
- ✓Fixing a GSTR-1 error in the next month without checking the effect on GSTR-3B.
- ✓No owner or checklist, so the return is prepared by whoever has time.
Due dates and rules
Due dates, thresholds and filing options change over time. Always confirm the current position on the GST portal or with your CA before filing.
Want your whole team to work this way?
We teach this hands-on, onsite at your office, and test every trainee. See Corporate GST training for accounts and compliance teams.
Get a quote