If you are using new General Ledger Accounting and also using customer-defined fields, these fields are generated to the appropriate compatibility views.

During view generation, which is part of the migration to S/4HANA, only customer-defined fields that already existed before its introduction are taken into account.

Enhancements of the existing data model are not allowed. Enhance the new data structures instead, and use the coding block to do this. For more information about using views GLT0, FAGLFLEXT, FMGLFLEXT, PSGLFLEXT, and JVGLFLEXT in customer-defined programs, see SAP Note 2221298.

For customer fields in BSEG and the index tables, note the following for the creation of the views with the same names:

If a customer field exists in both BSEG and in the indexes, it is automatically generated into the view with the same name. It is not transferred into a view with the same name if the customer field only exists in the index. In this case the field must first be included in the BSEG and filled using a customer program.

If you transferred data from your Z tables to new General Ledger Accounting during the migration to the Financial Accounting Add-On 1.0, you have to delete the data of these Z tables before the migration to SAP S/4HANA Finance, On-Premise-Edition. If you do not delete the data, the data of the Z tables is migrated again and transferred to the new table structure. The values would then be duplicated.

If you have used interfaces to connect your system to external systems that make postings to General Ledger Accounting (in real time or subsequently), check whether adjustments need to be made to the interfaces. For more information, see FI-GL (New), Transfer of Totals and Single Documents in Distributed Systems.

In SAP S/4HANA Finance, there is only partial support for ALE scenarios. An SAP S/4HANA Finance system cannot serve as an ALE receiver for CO line items. The reason is that FI and CO line items use the same persistence table in SAP S/4HANA Finance. Therefore, the CO line items cannot be posted alone without the FI line items they belong to. SAP does not provide a check to determine if this scenario is used in the system. You have to check this manually. ALE scenarios for the distribution of CO master data, such as cost centers, continue to be supported.