Compliance calendarApplies to someApplies to some
Statutory deadline
GSTR-6 and IFF due date
Two different obligations that happen to share a day of the month: the ISD return, filed every month, and the optional QRMP invoice upload, which only applies after the first two months of a quarter.
GSTR-6
Input service distributor return for last month
Falls due
13th of every month
Applies if
you are registered as an Input Service Distributor (ISD)
IFF (optional)
Optional upload of B2B invoices for the first or second month of a quarter, so your buyers can claim the credit early
Falls due
13th of the month after the first and second months of each quarter
Applies if
you file under QRMP and want to pass credit to buyers before the quarter ends
Extensions happen. These are the statutory dates. The CBIC and CBDT extend them often enough that you should confirm against the official portal before relying on one — particularly in the first year of a change. Cortex warns you ahead of the statutory date, which is the one you can plan around.
Stop tracking this by hand.
Cortex shows the statutory dates that apply to you on your dashboard and compliance calendar, ahead of the day, alongside your receivables, your payables and the MSME 45-day clock. Upload a Tally, Vyapar or Busy export and it reads your numbers as they come.
General information, not tax advice. Your own dates depend on your registration, turnover and constitution — check with your CA.