Penalty notices of up to £207.50 a day may apply if the guidelines from the only other UK scheme - in Nottingham - are followed.
The proposal was at the heart of a budget deal struck between the Greens and the Scottish Government and will see councils handed the power to introduce such a charge.
The tax could amount to around £500 a year for workers and £415 for employers.
Tory finance spokesman Murdo Fraser said the fines could run into “hundreds or indeed thousands of pounds” per day for firms.
“It’s yet more evidence that this scheme should be dropped at once,” he said.
“It’s bitterly unfair on the thousands of workers across Scotland who have no choice but to take their car to work.
“The SNP is making life hard enough for businesses in Scotland to thrive – this latest tax raid will only compound that misery.”
Guidelines issued in Nottingham state that businesses would receive fines for not complying.
They state: “Where any workplace parking is being provided at premises without a licence, or the licence does not cover all the workplace parking spaces, the Penalty Charge Notices (PCNs) will be for 50 per cent of the annual charge per unlicensed place for each day a contravention occurs.”
The plans have already met with a backlash from business and motoring organisations.
It emerged yesterday that teachers could seek compensation if they are forced to pay the parking tax. Hospital staff have already been told they will be exempt from the charges.
The Education Institute for Scotland (EIS) said its members would want recompensed if councils pushed ahead with the levy in schools. General secretary Larry Flanagan said the union would reclaim the costs in future pay negotiations.
“If you’re talking about £500 a year being taken out of your salary that’s the kind of figure we’re fighting to try and get added in as part of the compensation,” he said.
Borders, Dumfries and Galloway and North Ayshire councils have all ruled out using the levy, but Edinburgh Council Adam McVey says the cpaital will consider it.
A Scottish Government spokesperson said: “The Workplace Parking Levy would be introduced at the discretion of local authorities, based on local circumstances, so any predicted costs to businesses or individuals are purely speculation at this point.
“We will be engaging with the Green Party and stakeholders in the run-up to Stage 2 of the Transport Bill to help shape the specifics. The amendment will then be subject to the normal parliamentary scrutiny and approval.”