Hello Madam, thanks for responding.
Also thanks to Sadanand Sir and Kasturi Sir for your valuable insights.
The scenario Im focused is where job worker sells scrap on account of principal (if agreed).
As far as I know about industry practice, it is mostly job worker who sells the scrap.
Seldom a principal would be interested to take it back or sell on his invoice to a party other than job worker.
It is convenient for principal because he is concerned with outcome of the job work and not worrying about where to sell scrap.
To summarize,
There is no doubt that if job charges are reduced on account of retention of scrap or its proceeds, then taxable value for job charges will be Monetary consideration + value of scrap for purpose of GST calculation and its payment thereon.
Possible Accounting treatment could be either,
Principal sells scrap to Job worker (easy for auditing) or
Job worker issue a financial credit note if he is selling on Principals account, reduce total receivables. (Much leaner accounting practice)
GST credit note cant be issued since it will also reduce GST liability linked to job work service invoice.
I hope above explanation is agreeable.
With regards to quantity to be sent back. I have a follow up query.
If scrap is sold by job worker(if agreed) then quantity returned will not include qty of scrap sold or left with job worker.
Eg. 200 sent for job work, 20kg scrap sold, then quantity returned to principal would be 180kg.
Thanks.