Landlords may have to register their empty storefronts with the city or face a fine, if an ordinance approved Monday by the Board of Supervisors Land Use and Transportation Committee becomes law.

While there is a glut of vacant storefronts around San Francisco — they’re especially prevalent in the Haight, the Richmond and North Beach — the city does not have a full picture on how many there actually are. That’s because of a loophole in the building code that says a commercial storefront is not considered vacant if it is “actively being offered for sale, lease or rent.”

The Department of Building Inspection also requires landlords to register empty properties within the city, but the database doesn’t show the full picture because it is complaint-driven and self-reported.

The ordinance, written by Supervisor Sandra Lee Fewer, would close these loopholes by requiring building owners to register a vacant or abandoned storefront within 30 days of it being empty, regardless of whether it is advertised for sale or lease. The annual registration fee would be $711. Businesses which do not comply would face a one-time penalty of $2,844, four times the registration fee.

“Better tracking will help ensure that vacant storefronts are promptly identified, registered and monitored to remain safe, and avoid hazards and nuisances resulting from being vacant or abandoned,” Fewer said.

The ordinance, sponsored by all 11 supervisors, will move the full board March 5.

Supervisor Aaron Peskin also plans to propose a measure for the November ballot that would tax property owners with consistently empty units.

— Trisha Thadani

Email: cityinsider@sfchronicle.com, tthadani@sfchronicle.com