A passing score is the score set by the ICC and/or/with the Exam Development Committee (EDC) as the minimum score needed to pass the exam. This score is technically called a scale score and is set as 75 for the National Certification exams.
Most Contractor/Trades examinations require a candidate to answer at least 70 percent of their questions correctly in order to pass the exam. It is important that you carefully read the relevant bulletin or contact the licensing agency for information regarding their minimum passing requirement.
We recommend checking out THIS article on scaled scoring to understand a little more on how scoring works.