create a saved search for customer who don’t have contacts
for this we need to write a simple saved search with the help of basic criteria and result we can achieve this .
first got to new saved search and select a customer type
then give a name and id and make it as public that can be visible for other account as well
and the criteria according to your requirement
in result tab you can add what field u can required in saved search result.
then Click save and run u will get the result u can add any expression if you what.