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