See if your college accepts the exam you want to take.
Read the CLEP policy on your college's website to see if they grant credit for the CLEP exam subject you're interested in taking.
Find out if the exam you want to take counts toward your degree.
Consult your college's degree requirements or talk to your academic adviser to see if the CLEP exam you want to take fulfills a requirement for the degree you are pursuing. If you're in the military, talk to your veteran affairs office or education service officer. Note that at some colleges, a successful CLEP score will let you skip a course that would otherwise be required (either as a general requirement or as an introductory course within a major).
See if your college's policy has any restrictions that might affect you.
Some colleges won't grant credit for a CLEP exam if you've already attempted a college-level course closely aligned with that exam. For example, if you successfully completed English 101 or a comparable course on another campus, you wouldn't receive CLEP credit in that same subject.