SELECT *
  FROM INFORMATION_SCHEMA.ROUTINES
 WHERE ROUTINE_TYPE = 'FUNCTION'
   AND OBJECTPROPERTY(OBJECT_ID(QUOTENAME(SPECIFIC_SCHEMA) + '.' +
QUOTENAME(SPECIFIC_NAME)),'IsMSShipped') = 0

oder alternativ dazu:

SELECT *
  FROM sys.sysobjects -- oder sys.objects
 WHERE type IN ('FN', 'IF', 'TF')

SELECT *
  FROM sys.sql_modules
 WHERE OBJECTPROPERTY(OBJECT_ID,'IsScalarFunction') = 1
    OR OBJECTPROPERTY(OBJECT_ID,'IsTableFunction') = 1
    OR OBJECTPROPERTY(OBJECT_ID,'IsInlineFunction') = 1