I was given a task to block duplicate records from being created when a soap webservice brings records into netsuite. the records contain an ID from the external system. Netsuite will generate its own ID so they asked me to use the ID from the external System to be used as a check before the record is created. is this as simple as writing a UE that does a search for the record i dont want duplicated which contains the ID from the external system and if records found is greater than 0 - throw an error?

If you use the netsuite native

externalid

field you get duplicate prevention built-in.