Group Invoices from different sites

Hi all,
I want to combine invoices from three sites (plants) into a single invoice for the customer.
Does anybody know how to do this?
Thanks
Andy

Its possible with few BPMs and posting rule change.

Hi,
Is there no standard way of achieving this?
Invoices are site specific so how would you include in a single invoice?
Thanks
Andy

Epicor creates invoice per plant only. Either go with CSG or develop a BPM and posting rule change to achieve.