BAdI SD_SLS_MODIFY_HEAD is not called as expected when processing an Invoice

[SAPSupport]

1. We have created a new custom field and are filling it through a custom logic via SD_SLS_MODIFY_HEAD, but the new value is not transferred.
2. We create sales order 123 on our system. We later adjusted the logic in BAdI SD_SLS_MODIFY_HEAD to fill a custom field with text "TEST". When we create/process the billing document for sales order 123 we expect to see this custom field filled with the text "TEST" as per the new logic.

------------------------------------------------------------------------------------------------------------------------------------------------
Learn more about the SAP Support user and program here.

[SAPSupport · Accepted solution]

Please note that the BAdI SD_SLS_MODIFY_HEAD is used for sales orders. It is not called during invoice processing. Before creating the invoice, please try making a relevant change to the sales order or creating a new sales order - the BAdI will be called as expected. 

If you are ever unsure if your BAdI is getting called, please consider using the Custom Logic Trace. See link below:

https://help.sap.com/docs/SAP_S4HANA_CLOUD/0f69f8fb28ac4bf48d2b57b9637e81fa/4161479993824dde8f088419...

It maybe another option for you to consider using Data transfer BAdI:

https://help.sap.com/docs/SAP_S4HANA_CLOUD/a376cd9ea00d476b96f18dea1247e6a5/3714184b72b54dad819a7c39...