The number of written theory exams required for a Commercial Pilot License (CPL) varies by aviation authority. For example, the Federal Aviation Administration generally requires one main CPL knowledge exam, while the European Union Aviation Safety Agency requires multiple subjects, often around 13 theory papers for ATPL-integrated training. Authorities like the Directorate General of Civil Aviation also require several papers covering navigation, meteorology, regulations, and technical subjects. Overall, the number and difficulty of exams depend on the country’s aviation regulations and training pathway.