Currently there is a single language string, "HomePage_BarcodeExpireSoon" that governs the orange notification on the home screen for patrons with accounts 'expiring soon.' Admin settings allow you to set when this popup appears and I think it's anything from 30 days to 0 days before the patron's expiration date. However, the same text continues to appear for a patron whose registration is expired, so you can't use "your account is expiring soon" because that gives an expired patron the impression that their account is not yet expired.

There should be one language string for 'expiring soon' and a separate one for 'account expired.'