In SAP sales & distribution module, an inter company sales occurs when the selling organization belongs to a different company code than the delivering plant. The transaction path for accessing inter company sales billing is:
IMG >> Sales and distribution >> Billing >> Intercompany billing
Let us take an example to understand inter company sales better. Suppose there are two company codes namely 1000 and 2000. A customer may place an order for goods in sales organization belonging to company code 3000. However, the goods may be manufactured by a delivering plant belonging the company code 1000. A sales order is created indicating delivering plant of company code 1000. The sales organization then invoices the customer for the materials purchased. SAP R/3 automatically creates an inter company billing document at the same time as the customer’s billing document is created. This inter company invoice is sent from the delivering plant to the selling sales organization.
As a rule of thumb, when dealing with different company codes, one may find a need to transfer stock between two different company codes. However, if the stock be transferred within the same company code, there is no need for an inter company transaction. But in case the stock is transferred between different company codes, a transfer of value occurs and is an inter company sale.