issue of taxable invoice under GST

Sreevidhya V (405 Points)

19 February 2018  
we are a manufacturer of textile goods.85% of production done by us and at the end 15% done by job work.the buyer is an exporter who raises PO on us.
now after completing job work only we can send the material to buyer.

he is not ready to give advance without taxable invoice. even against proforma invoice buyer not giving advance.
without advance it wud b difficult to get working capital.

can we raise a taxable invoice under gst to him before removal of goods?? if so how many days before removal of goods can we raise invoice. pls advise