Why deadlines matter more in 2026
Missing a GSTR-1 due date does not just trigger a late fee — it can block ITC for your buyers, delay GSTR-3B reconciliation, and create a compliance trail that is hard to unwind.
Whether you file monthly or under the QRMP scheme, keeping a single calendar for every GSTIN is the simplest way to avoid last-minute portal rush.
Monthly filers — key dates
For taxpayers with aggregate turnover above the QRMP threshold, GSTR-1 for a given tax period is generally due by the 11th of the following month.
Build an internal cutoff: freeze invoice data by the 8th, run validation on the 9th, and reserve the 10th for partner or client review before submission.
- Set automated reminders 7, 3, and 1 day before each due date.
- Maintain a checklist: HSN summary, B2B vs B2C totals, and credit/debit notes.
- Export a filing log with ARN and timestamp for every GSTIN.
Quarterly filers (QRMP)
Quarterly GSTR-1 filers must still respect IFF (Invoice Furnishing Facility) windows if they choose to report large invoices monthly within the quarter.
Map each client's filing type in your dashboard so you never apply a monthly deadline to a QRMP profile.
How automation helps
GST Bharo tracks filing status per GSTIN, surfaces overdue returns, and pre-validates summaries before portal upload — so your team spends time reviewing exceptions, not copying numbers.