GSTR-1 is the foundation return under GST, as it captures outward supplies and determines the recipient’s input tax credit eligibility. Errors in GSTR-1 do not remain confined to the supplier—they directly impact customers, vendor relationships, and audit exposure. A correctly filed GSTR-1 is therefore not just a compliance task but a commercial responsibility.
1. Introduction
GSTR-1 is a statement of outward supplies to be furnished by every registered person (other than composition taxpayers) for a specified tax period. It feeds data into:
recipient’s GSTR-2B,
GST analytics systems, and
audit and scrutiny modules.
A wrong GSTR-1 creates problems for two taxpayers, not one.
2. Who Is Required to File GSTR-1
GSTR-1 is required to be filed by:
regular registered taxpayers,
exporters and SEZ suppliers, and
casual taxable persons.
Composition taxpayers and certain notified categories are excluded.
3. Frequency of Filing
GSTR-1 can be filed:
monthly, or
quarterly under the QRMP scheme.
The filing frequency must align with:
turnover limits, and
option exercised at the beginning of the year.
Mismatch in frequency selection leads to portal errors.
4. Due Dates for GSTR-1
Due dates depend on filing frequency:
monthly filers — prescribed monthly due date,
QRMP filers — quarterly due date, with IFF option for B2B invoices.
Late filing attracts late fees and blocks further returns.
5. Structure of GSTR-1 — Table-Wise Overview
GSTR-1 consists of multiple tables capturing different types of outward supplies, including:
B2B supplies,
B2C supplies (large and small),
exports and SEZ supplies,
credit/debit notes, and
advances and adjustments.
Understanding table applicability is critical.
6. Table 4 — B2B Invoices
Table 4 captures:
supplies made to registered persons.
Key points:
correct GSTIN of recipient,
correct invoice number and date, and
correct tax rate and place of supply.
Errors here directly block recipient’s ITC.
7. Table 5 — B2C Large Invoices
This table includes:
inter-state B2C invoices exceeding the prescribed value threshold.
Correct place of supply and state code are mandatory.
8. Table 7 — B2C Small Supplies
This table captures:
intra-state B2C supplies, and
inter-state B2C supplies below threshold.
State-wise reporting accuracy is essential.
9. Table 6A / 6B — Exports and SEZ Supplies
These tables capture:
exports with or without payment of tax, and
supplies to SEZ units or developers.
Shipping bill details and LUT references are critical.
10. Credit and Debit Notes Reporting
Credit and debit notes must be reported:
with correct original invoice linkage, and
within prescribed timelines.
Incorrect reporting causes reconciliation issues.
11. Advances and Adjustments
GSTR-1 requires reporting of:
advances received for services, and
adjustment of advances against invoices.
Failure to track advances leads to mismatch with GSTR-3B.
12. Amendments in GSTR-1
Amendments to earlier returns can be made through:
specific amendment tables.
However:
amendments are time-bound, and
incorrect original reporting increases compliance burden.
Amendments fix errors, but also expose audit trails.
13. GSTR-1 and GSTR-3B Reconciliation
Outward supplies reported in GSTR-1 must:
match tax liability paid in GSTR-3B.
Mismatch is one of the most common scrutiny triggers.
14. Common Errors in GSTR-1 Filing
Frequently observed errors include:
wrong GSTIN or state code,
incorrect tax rate,
duplication or omission of invoices,
mismatch with accounting records, and
late reporting of credit notes.
Most GST notices originate from these mistakes.
15. GSTR-1 During GST Audit and Scrutiny
During audit, officers verify:
consistency between GSTR-1, books, and GSTR-3B,
impact on recipient ITC, and
amendment patterns.
Repeated corrections raise red flags.
16. Practical Guidance for Businesses
Best practices include:
reconciling sales registers with GSTR-1 monthly,
validating customer GSTINs,
reviewing place of supply logic, and
avoiding last-day filing.
Accurate GSTR-1 builds compliance credibility.
17. Practical Guidance for GST Practitioners
Practitioners should:
design invoice validation controls,
conduct pre-filing checks,
review amendment impact carefully, and
educate clients on downstream ITC consequences.
GSTR-1 accuracy is a professional responsibility.
18. CABTA Insight
“GSTR-1 is not just a return — it is your GST footprint.”