Extension Ledgers in S/4 HANA

Hello All,
Will try to explain the concept of Extension ledger in comparision to standard ledger with my recent experiences of projects.
Extension ledgers are one of the powerful options that can be used for Management reporting. These ledgers staple the data on top of Standard ledgers,hence no data duplications as number of extension ledgers can point to 1 Standard ledger.There are 2 types of ledgers in SAP S/4 HANA:

1. Standard Ledgers
2. Extension Ledgers

Comparision of Standard Ledger and Extension Ledger:

Standard Ledger	Extension Ledger
This is an independent ledger and standard ledger is an underlying ledger.	The underlying ledger is a standard ledger.
Postings made to standard ledgers will only be reflected in standard ledger.	Postings made to standard ledger will form part of reports of extension ledgers linked to standard ledger.
Total Balance = Balance in Standard Ledger	Total Balance = Balance in Standard Ledger + Balance in Extension Ledger
Postings can be specifically made in standard ledger	Postings can be specifically made in extension ledger
If you are on Classic GL and migrate to S/4 HANA, you cannot activate standard ledgers on day 1 (Subsequent activation of standard ledger is possible though)	Extension Ledgers can be activated in S/4 HANA even if you were on classic GL in ECC.
Many Standard ledgers can be created to reporting	Many Extension ledgers can be added on top of Standard ledger. (N:1 is possible)

When Extension ledgers can be activated?

1. This can be activated in S/4 HANA.
2. Unlike standard ledgers, Extension ledgers can be activated in S/4 HANA even if you were not on New-GL and not used Ledgers in ECC.
3. Extension ledgers are non-disruptive, hence can be actived at any period of time.

Where is the data of Extension ledger stored?

• It is stored in ACDOCA table only.
• Postings made to standard ledger are not stored in extenstion ledger specifically.(below example will help you in better understanding)

Example: You have your standard ledger as 0L and Extension ledger as ZX .

1. If you post a document to 0L. ACDOCA will be updated with ledger posting to 0L only, However when you try to extract reports like FAGLL03  for ledger ZX, all the postings of 0L+ZX will be calculated for balances.
2. If you post a document to ZX. ACDOCA will be updated with ledger posting to ZX only,hence influencing the balances of ledger ZX.

Config: The setup of extension ledger is very simple.




I will try to update this blog with use cases for extension ledger. Happy to get some suggestions and use cases in comments.

Thanks
Praful Jain.


Source: https://blogs.sap.com/2019/01/15/extension-ledgers-in-s4-hana/