He said drivers for ride-services also fall into that category and that his office often doesn't have mailing addresses or email addresses of those drivers, therefore making it impossible to deliver notices and collect fees.
"I hear you," Cisneros said to the taxi drivers. "We absolutely enforce the law."
But Cisneros admits that the law isn't perfect and his office doesn't have the manpower to canvass the streets in search of rogue drivers.
Barry Korengold, who has been driving a taxi since 1987 and is on the executive board of the taxi alliance, said he thinks Cisneros needs to require ride-service drivers to register.
Korengold said that the taxi company he drives for instructed him to register with the city. If he doesn't renew that registration, and pay the $91 annual fee, the city has his contact information and would levy penalties against him.
Ride-service drivers aren't compelled to register and won't receive penalties because the city doesn't know who they are or how to contact them, Korengold said.
He said the treasurer should require employers, such as Uber, Lyft, Sidecar, Wingz, and others, to notify their drivers of their legal responsibilities to the city.
Korengold said the city's board of supervisors ought to craft an ordinance to allow for increased oversight of these drivers operating businesses on the city's roads.
He suggested a sticker be placed on the driver's vehicle to prove their registration.
Other taxi drivers who gathered at city hall today said they felt that the city is discriminating against them with the unfair application of the city's business registration fee.
The taxi alliance maintains that preferential treatment for the ride-service companies extends past the registration fee to background checks, training, insurance, and vehicle inspections.
The taxi alliance's letter to Cisneros states that as a result of that preferential treatment, taxi drivers' incomes have been "catastrophically cut" and that, "as many as 40 percent of drivers are now earning below minimum wage on shifts. Many of us are immigrants with few options to support our families - taxi driving is the only way we house, feed and clothe our families. Our families are suffering."
Cisneros said today's Taxpayer Assistance Day event held at City Hall was designed to help all taxpayers complete their business registration renewal by the Monday deadline. He said they can also register online.
He encouraged everyone doing business in San Francisco to register or renew their business by the deadline to avoid additional fees, interest, and penalties.