Split Billing...

SUGGESTED

I have a client where I have set up split billing. I have entered time and it comes up as I want it so far. This was a partnership which has now dissolved. The main client has additional work we have done that no longer invoices the sub client. I want to bill both but 2 slips are not to be split. Is there a way I can do that on one invoice or do I have to bill the split and then bill the separate later? thanks in advance!