GST on Post-OC Installments – Payment Milestones Were Date-Based, Not Construction-Linked

Have you paid any amount in OCT 2025 , while booking the Flat ? , and balance instalment. , you are paying after the Occupancy Certificate . 

the builder might argue that the agreement was done before the OC and therefore I must pay full. Though the agreement says subject to the taxes applicability.

yes I paid the 80% of the amount in October 2025 and balance installment I am paying based on the dates agreed in the agreement.

ok , if you have alrady paid  80 % of amount  before OC and sale agreement also before OC ( under construction )  , then  on  all  the balance installment  GST may applicable , because  as per  schedule II ( sub section5(b) )of the CGST Act 2017 ( please refer ) , if the entire considration has been received after the issuenace of  OC from the Compentant Authority then GST not applicable .

As per section 13 of the CGST Act 2017 , time of supply , meaning thereby liability to pay gst arises , at time of issuance of Invoice or payment whichever is earlier , so GST liability arises when 80 % ampunt  paid . 

So in your  case 80 % amount paid before part OC and on balance on installment GST will not applicable beacause you have recived Part OC as per your query ,  there is space to agrue that on considration payable after the part OC , GST will not applicable , and also full OC will be for entire project . 

In my opinion you take Advnace ruling under section 97(1)(e) of the CGST Act 2017 . Also take more Opinion on this as well  . 

Thanks for your feedback.

I have a concern that builder will not give the position if I am not clearing all the dues and its a reputed builder so backed with full legal team therefore I would have to contest after the posession

Can you cite any High Court judgment, Supreme Court judgment, AAR or CBIC Circular that specifically supports the proposition that GST is not payable on consideration becoming due after Part OC where the Agreement for Sale was executed before the OC?

also with my research I find the ambguity in the law 

you mentioned

"GST liability arises when 80% amount paid."

I don't think that's the correct legal reasoning.

Section 13 of the CGST Act deals with time of supply, but in my case the real issue is:

Was there still a taxable supply of construction services after the Part OC?

that is what the builder can argue.

Thanks for your feedback.

I have a concern that builder will not give the position if I am not clearing all the dues and its a reputed builder so backed with full legal team therefore I would have to contest after the posession

Can you cite any High Court judgment, Supreme Court judgment, AAR or CBIC Circular that specifically supports the proposition that GST is not payable on consideration becoming due after Part OC where the Agreement for Sale was executed before the OC?

also with my research I find the ambguity in the law 

you mentioned

"GST liability arises when 80% amount paid."

I don't think that's the correct legal reasoning.

Section 13 of the CGST Act deals with time of supply, but in my case the real issue is:

Was there still a taxable supply of construction services after the Part OC?

that is what the builder can argue.

Is Part of O/C is  ready to Move in the Falt , like  Full OC after completion , if legal  answer is yes , then it is part of  Litigation.

This is a contested area in GST on real estate but you have a strong position here.

The core principle: GST on under-construction property applies to the supply of construction services. Under GST law, that supply is considered complete when the Completion Certificate or Occupancy Certificate is obtained. Post-OC, the residential property becomes a completed asset, and sale of a completed residential unit is EXEMPT from GST under Schedule III of the CGST Act.

For installments due after January 12, 2026 (OC date):
- If the payment milestone is factually and contractually post-OC, the builder has weak grounds to charge GST
- The builder cannot treat a completed asset as under-construction merely because the sale agreement was signed earlier
- Your agreement clause "subject to taxes applicability" actually supports your position ,  taxes applicable at the time of payment, not at booking date

Practical steps to push back:
1. Obtain the OC date in writing (January 12, 2026) from the builder or RERA records
2. Write to the builder pointing out both the March and August 2026 installments fall after OC
3. Request a revised invoice without GST for these installments
4. Ask the builder to cite the specific CBIC circular or advance ruling they rely on ,  they typically cannot

Builders routinely collect GST on post-OC amounts because buyers do not push back. If you have already paid GST on a post-OC installment and demand it back, the builder should reverse it or you can seek a refund through the GST portal.

For context on GST applicability at different construction stages, this guide covers the construction-stage versus completed-property distinction under GST: https://taxgarden.in/blog/gst-on-self-construction-house-building-own-use-india-2026

Thanks but there are three statements that I would need them to be backed by authority.

1. "Sale of a completed residential unit is EXEMPT under Schedule III"

The CGST Act says that sale of land and, subject to paragraph 5(b) of Schedule II, sale of a building is neither a supply of goods nor a supply of services (Schedule III). The words "subject to paragraph 5(b)" are critical.

paragraph 5(b) itself deals with construction intended for sale before completion

2. "Taxes applicable at the time of payment, not booking"

need citation of any section, notification, or judgment for it.

If there were a Supreme Court or High Court decision saying that GST applicability is determined solely at the time each installment becomes payable, my case would be much stronger. So appreciate if it can be backed by authority. 

3. "You can seek a refund through the GST portal"

I  cannot simply log into the GST portal and claim a refund as a buyer.

If GST was charged and remitted by the builder, recovering it usually requires:

• the builder issuing a credit note and adjusting the tax, or
• a legal process if the builder disputes liability.

So that part of the advice is oversimplified unless there is a simple way that I am not aware of ?