I would appreciate views from GST professionals on the following situation:

  • Apartment booked in October 2025 (under construction).
  • Part Occupancy Certificate (OC) issued on 12 January 2026.
  • apartment is covered by the Part OC.
  • The remaining payment milestones were fixed calendar dates (15 March 2026 and 15 August 2026), not linked to construction milestones.
  • The builder issued fresh demand-cum-tax invoices after the OC and charged GST on these installments.
  • Possession was offered only after the OC.

My question is:

Is GST legally payable on installments that become due only after the Occupancy Certificate, where the apartment is already covered by the OC but the Agreement for Sale was executed before the OC?

Are there any CBIC circulars, Advance Rulings, High Court, or Supreme Court judgments dealing with this specific fact pattern?

Thank you.