Payment to builder

Adv. Kiran Marathe (NO) (193 Points)

05 June 2018  
our client have​ brought a flat in april 2016 and some amount is due for payment to the builder. the due payment is rs 5,00,000 lacs. now builder is demanding gst on rs5,00,000. is it needed to pay gst on the due payment. agreement is done in april 16.