Non-residential property owners can apply for credits from any or a combination of the categories listed in Credit & Appeals Manual. The maximum allowable credit is 42% of the gross billing amount for commercial, industrial, tax-exempt and non-profit, institutional, HOA common areas, multi-family (duplexes and townhomes not subdivided by parcel lines), boat slips (dry stack marinas), and properties whose primary function is not a single-family residence or mobile home residence, regardless of how many individual credits for which the property qualifies.