Job work

Dear Sir,

We are doing jobwork for autoparts, kindly clarify the below mentioned query.

for example. "A" selling to "B" and material delivered in "C", ( here C is the jobworker ) C is doing jobwork and raise the service invoice as well as delivery challan.

Now "B" is telling that "C" should refer the invoice / delivery challan numbers of both "A" and "B" with delivery challan. Is it mandatory becaues we had bill wise clearances details and we are doing reconsilation also.