It would be wonderful if Koha had the ability to generate a notice to send to patrons when their account is charged, billed, or incurs a fee. Currently the ODUE3 notice often functions as a billing notice for overdues, but it is connected to the overdue calendar and not necessarily when the longoverdue cron actually charges a patron, so it can take work to match the schedules. Additionally, it would be nice to have the ability to send billing notices for instances other than overdue items. It would likely need to be configurable for which types of fees, or what amounts, trigger notices and which don't, or only for certain types of fees.