If you want to invoice more than one shipment at a time, you can use the combined shipments feature.
Before you can create a combined shipment, more than one sales shipment for the same customer in the same currency must be posted. In other words, you must have filled in two or more sales orders and posted them as shipped (but not invoiced).
Fill in the invoice lines by copying the information that is already recorded on the sales shipments:
Open the 
Sales Invoice
window.
On the sales invoice, click the first invoice line.
Click Functions, Get Shipment Lines. The Get Shipment Lines window appears.
Select a shipment line that you want to include in the invoice, and then click OK to copy it to the invoice lines.
Repeat steps 3-4 to copy other shipment lines to the invoice.
If a customer is also recorded as a contact in the Relationship Management application area, and if you have specified an interaction template code for shipments in the Relationship Management Setup window, when you click Print to print the shipment, the program automatically records an interaction in the Interaction Log Entry table.