What expense category do folders come under?

This is a difficult question to answer definitively because it depends on how the folders are being used. If the folders are being used to store receipts, then they would likely fall under the 'office supplies' category. However, if the folders are being used for marketing purposes, then they would likely fall under the 'marketing' category. Ultimately, it is up to the business owner or finance team to decide which category is most appropriate for the folders.