This is one of those blog posts that might mostly be for the hive mind and Googling.
When posting an invoice, Business Central will aggregate the sales G/L post based on identifiers. So if two sales lines generates the same G/L sales post, it will just be aggregated into one G/L Journal Line (and one G/L Ledger Entry).
We frequently get the question, “Why does Dynamics NAV post additional output when I change a Production Order status to Finished?”
The scenario:
You create a Released Production Order for Quantity = 10. During the course of production, you record the output of 5. When you change the Production Order to Finished, NAV automatically records an additional output of 5.