If the tax code is changed in preliminary documents, it's not copied to billing documents.
SAP S/4HANA Cloud Sales Billing
Reproducing the Issue
- Go to app "Change Preliminary Billing Documents". Change the tax amount to some other value other than the defaulted one.
- Go to app "Manage Preliminary Documents". Create a billing document with reference to the preliminary billing document.
- Go to app "Display Billing Documents". The tax amout is not the value you changed.
When creating a billing document with reference to a preliminary billing document, the system uses the pricing type "G Copy price elements unchanged and redetermine taxes" internally. This is hard-coded. See SAP Note 24832 which explains different pricing types.
You can change the tax amount manually after the billing document is changed. Or as a workaround please check if you can make user of the data transfer cloud BAdI SD_BIL_DATA_TRANSFER (Custom Data Transfer for Billing Documents) and change the pricing type according to your own need.
24832 - Pricing rules/TVCPF
pricing type G, preliminary billing document, tax code, change, tax amount, re-determine , KBA , SD-FIO-BIL , Fiori UIs for Billing , Problem