The identification code of a drug is defined as “a code for identifying tablets, etc.” and is described in the “Composition/Properties” section of the package insert. We investigated whether the Pharmaceuticals and Medical Devices Agency (PMDA) website, which allows users to search package insert information, can be used for drug identification using identification codes in 2019 before the new package insert guidelines were implemented, and in 2022, during the revision period. Approximately 30% of the investigated high-risk drugs were unidentifiable in both years. The most common reason was that images were used to register identification codes on the PMDA website, and character strings were not searchable. We then conducted a questionnaire survey of pharmaceutical companies, and only approximately half of the respondents opined that it would be preferable if the registration format for identification codes was established within the pharmaceutical industry. However, hospital pharmacists urged for more simplified identification of drugs on the PMDA website.