Lots of application...noob question

[Alnie F.]

I am helping a friend rent her place. The rental rate is way below market here in the San Francisco Bay Area so for single day I had 16 showings and at least 5 applicants, with more to follow who will be sending me their applications online.

Do I have to run credit on all those who applied and paid or can I just shortlist the top 5 based on the answers to the application form and charge only the shortlisted applicants $35 for credit/background check?

I just feel bad having people pay $35 if I know they are not going to make the shortlist but want to make sure I'm not breaking any discrimination laws.

Thanks in advance for your help.