Depending on the document type, document numbers are either internally assigned by the system or entered by you externally. Each document type has a specific number range from which the document number is selected. If the number range determined by the document type stipulates external number assignment, you enter the document number here. The system then checks whether the number lies within the permitted number range, or whether it has not yet been entered.

If you enter documents using internal document numbers, make sure you write the SAP document number on the printed invoice and then file the original document under this number. In this way, you can refer to the SAP document in the system from the original document (on paper) in your files or you can refer to the original document from the SAP document.

If you have installed the Sales and Distribution (SD) application component, your system administrator can configure the system so that either the invoice number from SD is used for the accounting document, or separate document numbers are assigned to invoices from SD. For more information, see the R/3 Library SD - Sales and Distribution.