"It was incredibly clumsy and thuggish," he said. "It's the kind of thing that makes people think that their elected officials are operating against them."

Thistel's company, which operates 20 vehicles, has software that will have to be updated — at a steep cost — to produce and track the information required under the new tax, he said. But other companies have no such technology.

"For the mom-and-pop [companies], I mean, think about the challenges for them," he said. "They have no database, they're driving, they do everything, and now they have to track the rides, the passengers, compile it and submit it every 30 days? It's going to be an administrative burden on them that they just won't do."

If smaller providers do not comply with the tax — not to mention new Web-based competitors such as Uber and Lyft, whose drivers have flown under the radar of regulators — slightly larger companies like his suffer, considering they are the ones the city is going to be able to enforce the tax on, he said.

"We're the only ones with the infrastructure to eventually comply with it, and nobody else will, so we'll be rendered instantly uncompetitive or at a competitive disadvantage," Thistel said.

Dwight Kines, a spokesman for Veolia Transportation, which operates the Yellow, Checker and Sun cab fleets in the city — about 550 vehicles — said Veolia has no intention of paying the tax for now.

Kines said he met with city officials on two occasions when the tax was being considered and was told that providers would be able to pass the tax on to passengers.

When it passed with no such language, he said, he sent a request to the Maryland Public Service Commission asking that a rate increase associated with the new city tax be included as part of broader rate negotiations that have been going on for years. The PSC controls taxi rates in Maryland.

Davis said the service providers or the city could make a formal request to the PSC asking for a rate increase based on the new tax, but Kines said he would have to rethink Veolia's approach given the city's stance.

Kines said taxi taxes aren't unheard of, but are more manageable in cities where fees are charged per trip, rather than per passenger, or where cabs are fitted with "smart meters" that can be manipulated to reflect the tax as an added fee to passengers.

Cabs in Baltimore do not have such meters, though they might agree to install them as part of the rate negotiations with the PSC, he said.

City Councilwoman Mary Pat Clarke, who met with several of the coalition leaders Tuesday, said she is working on legislation that would delay implementation of the tax while she and others work with the providers to find a solution.

"I wasn't trying to rescind the fee," said Clarke, but "to provide time to negotiate a different fee structure that is more practically accounted for, or at least delay long enough so that they can have the time and funding available to be able to meet the documentation requirements of the city."