The function modules in function group XLFX provide user exits for customer-specific field checks. They are always called before header data or item data is set in the internal tables.

• Header data check
• EXIT_SAPLWLF1_008

Function/Program:
• EXIT_SAPLWLF1_008: Enhancement: Fill/Change Customer Fields Header Data Billing Documents
• EXIT_SAPLWLF1_009: Enhancement: Fill/Change Cust. Fields Item Data Billing Documents