A customer file is an organized compilation of information about a company’s current and potential customers or consumers, primarily used for direct marketing campaigns. It can contain various data such as name, address, and telephone number, as well as more detailed information depending on whether it concerns individuals (General Public) or businesses (Business to Business). These files are generally managed electronically to improve automation and efficiency. They must comply with current postal standards and legal regulations regarding the protection of personal data, and be regularly updated to remain relevant.