Issue with Sales contract VAT update

Hi Experts,

I need your help on the below issue:

Requirement: I wanted to create Contract in SAP and update VAT number for European countries for Ship to partners in field STCEG.

Action: I am calling BAPI  BAPI_CONTRACT_CREATEFROMDATA to create the contract. Contract is successfully creating but will not be able to update VAT data for partner. So, I have used function module ' SD_CUSTOMER_MAINTAIN_ALL' to update the customer master. I am successfully able to update the customer master KNA1 and field STCEG (VAT) for the customer but VAT data is not visible when I check Ship To partner for Contract.

Can someone please suggest if there would be solution to get the updated VAT/STCEG data in Contract.

Thanks,

Pavan