What are the rules for retakes?

A retake is only permitted for a failed exam. If you pass an exam you are not allowed to retake it.

Each retake can only occur after a period of at least one month after the initial exam attempt. If you took a Combined Exam and want to retake a single part of that exam you must wait a month before the retake. If you took a single part exam and want to retake, but take the Combined Exam that contains the single part you must also wait a month.