The standard R/3 system uses different number ranges for billing and accounting documents. If you want to make the accounting document number the same as the billing document number, you can adapt the number ranges. Then both the SD and FI teams can refer to the billing document or accounting document without extra steps.
Key Concept
A document number identifies every R/3 transaction. This document principle in SAP ensures the transaction recording and offers traceability back to the originating transactions. Even casual SAP users are accustomed to many document numbers — for sales orders, purchase orders, delivery documents, material documents, accounting documents, Profitability Analysis documents, and so on. Each document type has a number range. Take the example of the document flow from SD. Figure 1 shows a typical SD document flow (transaction VA03> Document Flow) with various documents: sales order number, delivery number, transfer order, invoice, and FI document. The invoice 90023457 corresponds to the accounting document 100000029.

Figure 1
Typical SD document flow
The FI accounting document, in turn, can have various associated documents within FI or R/3 Controlling (CO). As shown in Figure 2, the associated accounting documents are for Profit Center Accounting, Special Purpose Ledger (SPL), Profitability Analysis (CO-PA), and CO. All the document numbers are different.

Figure 2
Document numbers in accounting
Some workarounds refer you to preceding or subsequent documents. For example, you can start in SD, view the invoice document with transaction VF03, and then view the corresponding accounting document number. Alternatively, you can search for the invoice number via transaction FBL5 (provided that the invoice number is populated on the accounting line items). Because the accounting document and billing document are linked internally, it is possible to view the relationship via document flow. Still, finding the accounting document number for the invoice number or vice-versa is at least a two-step process.
I'll show you how to save time by making the accounting document number equal to the billing document number. Let me first explain SD and FI document numbers and how they are connected. Once you understand the mechanics behind the link, the solution should be simple to understand.
SD Document Numbers
SD billing types manage the document number range in SD customization using transaction VOFA or menu path Billing>Billing Documents>Define Billing Types (Figure 3). R/3 assigns the number ranges for billing types (for example, F2 Invoice shown in Figure 3) under transaction VN01 (define number range for billing documents). The number range 19, which I use in this example, includes the document numbers shown in Figure 4. R/3 generates these document numbers. In Figure 4, the system would generate the next sequential number, 90034390, for the next billing document.

Figure 3
Billing type configuration

Figure 4
Document number ranges for SD documents
FI Document Numbers
A billing document acts as a bridge between SD and FI. Every billing document is sent to FI where R/3 creates another document under a separate document type. The document type defines the accounting document type created for the given invoice type (F2 in Figure 3).
When R/3 transfers billing document type F2 to FI, it creates another document with a separate document type. The accounting document type in Figure 3 is blank, which means it defaults to RV. The system configures the accounting documents in FI customizing via transaction OBA7 or menu path Financial Accounting Global settings>Document> Document Header>Define document types. Review the configuration for the accounting document types (RV in the example), as shown in Figure 5.

Figure 5
Configuration for accounting document type
The number range assigned to RV is 01, and the numbers allotted to 01 are shown in Figure 6. The FI document numbers are assigned via transaction FBN1 or menu path Document number ranges> Define document number ranges. The system automatically assigns internally generated FI document numbers. For example, the next time R/3 transfers the invoice 90034390 to FI, the accounting document number will be 100010249.
Note
This method does not apply to situations in which multiple document numbers are associated with one document, such as several sales orders, delivery documents, and purchase order documents. This is not possible because you can have multiple subsequent documents for the same source document.

Figure 6
Number ranges for accounting documents
Align SD and FI Document Numbers
Now that you understand the relationship between SD and FI document numbers, making accounting document numbers the same as SD billing document numbers is simple. The trick is to make the RV document number range the same as F2. In my example, the billing document range is 0090000000 to 0094999999, so you must make the FI document range the same. In addition, make the FI document number range externally generated, as shown in Figure 7. Using externally assigned numbers in this case means the system uses the billing document number and assigns it to the FI document number.
Note
When the Document type field is blank, R/3 defaults it to RV. If you want to map the billing document types to your own custom FI document type, you can configure it using transaction VOFA.

Figure 7
Make the accounting number range the same as the billing document number range
If you already have different number ranges for invoices and accounting documents, you can change the number range if you have plans to upgrade your system. You can also change it in your current productive system. As described above, use transaction FBN1 to change the number ranges for the specific number range object of accounting documents to match that of invoice documents. Make sure the number range is external. As usual, first test these changes in your sandbox to validate your results.

Mitresh Kundalia
Mitresh Kundalia heads the SAP practice at Quality Systems & Software (www.QSandS.com), a consulting firm specializing in SAP S/4HANA, SAP General Ledger, and complex System Landscape Optimization (SLO)-type reorganizations. Mitresh is widely acknowledged as a leading SAP expert, with multiple publications and an SAP-PRESS book to his credit. He has published more than 50 peer-reviewed articles and white papers, and he has given presentations at various SAP conferences and events. Mitresh is the chief solutions architect of General Ledger Migration Optimizer (GLMO), a leading product to accelerate and jump-start the SAP S/4HANA and SAP General Ledger initiatives; SAP Data Reorganization Optimizer (SDRO), an SLO-type product for managing complex system landscape reorganizations; and Group Currency Activation and Conversion (GCAC), a product suite to manage introduction of parallel currencies and conversion of data in a live SAP system.
You may contact the author at Mitresh@QSandS.com.
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