Financial accounting is an accounting method that companies use to disclose information to the outside world. Since the information is disclosed to external stakeholders, which can be regarded as the company’s performance, the reliability of the information is very important. There are various mechanisms to ensure or enhance the reliability of financial information, and internal audits are one of them. So my research questions are “how do internal audits affect the quality of financial information?” and “what is the relationship between external and internal audits?”. I use statistical methods based on publicly available data from companies to answer those research questions.