The qualified invoice storage method (invoice system) will be introduced in October 2023. As the introduction of the invoice system approaches, the increased workload on accounting departments and the need for system modifications are pointed out, but the reality is that many people do not have an accurate grasp of the entire system due to the wide range of areas affected. Therefore, this document summarizes the basic outline of the invoice system and the eight points to consider when dealing with the system in an easy-to-understand manner. We hope that this document will be of some help to those in charge of accounting and information system divisions throughout Japan who are considering the guidelines for dealing with the invoice system.