Sun certification exam vouchers are valid for any exam of the same price. Since the SCJP 1.4 exam costs the same as SCJP 1.5, I believe you don't need to exchange your voucher. Your voucher should allow you to register with Prometric for the SCJP 1.5 as well.
Just to be safe, though, you probably should call up your local Sun office to confirm that you can use your voucher for SCJP 1.5. As far as I know, the policy I described above should be applicable worldwide, but perhaps some areas may have special provisions that I'm not aware of.
Originally posted by Mohit Jain: Generally sun vouchers are valid for all sun exams that begin with 310 series. Preeti please check if your vouchers says so that it can be used for any sun exam of 310- series.
Not all exams, but only those of the same value as the voucher. While most exams do share the same price, a few (e.g. the SCJA exam and the SCJP upgrade) cost significantly less. You can't use the cheaper vouchers to take a more expensive exam.