In the event any business subject to a business tax closes or changes ownership, said business shall file a closing return with the city, in such form as the collector may prescribe, and shall pay the business tax due thereon within thirty (30) days from the time of closing or changing ownership of said business. A closing return shall be considered delinquent if not filed within the specified time. The processing fee for delinquent filings shall be ten dollars ($10.00) per month delinquent after the initial thirty (30) days. (Ord. 9517 § 1 (part), 1995: prior code § 6019)