BUC SALE

If the sale of the flat is made after obtaining a BUC certificate, GST is applicable, and the sale should be shown as a supply with a GST rte of 0% or under exempt sale in GSTR-1.

HSN summary is mandatory in B2C transactions if the value of the supply exceeds Rs.2 lakhs. If the value of the supply is less than Rs.2 lakhs,HSN summanry is not required.

For GST purposes, sale of a flat after the competent authority has issued the completion certificate—or after its first occupation, whichever is earlier—is outside the scope of supply under Schedule III. It is therefore not an exempt or zero-rated supply. Do not report it in GSTR-1 as a 0% B2C supply or under the exempt-supply table; that can wrongly treat it as a taxable supply at nil rate.

If the GSTR-1 portal requires an HSN summary, do not force the flat sale into the exempt HSN summary to clear the error. Check whether your return utility or portal version provides a separate field/category for supplies that are neither taxable nor exempt, or permits the HSN summary to be filed without this transaction. The exact portal validation can change; if it still blocks filing, raise a GST portal ticket and retain the completion/occupation evidence. This treatment assumes the sale was after the relevant completion certificate or first occupation.

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Flat sold after the building use (completion) certificate:

• Sale after the completion certificate isn't a supply (Schedule III), so no GST. ITC attributable to such units must be reversed (as exempt or non-taxable supply) under Rule 42, with the builder's special computation at project completion.