Four illegal taxi companies in Ottawa and their drivers face 112 charges after a nine-month City of Ottawa investigation.

The accused are to appear in court on Oct. 25, and if convicted, they could lose their drivers licences and face fines of up to $10,000, Susan Jones, the city's director of bylaw and regulatory services, said at a news conference Monday.

The charges were laid Friday under the Highway Traffic Act, and another 80 charges are pending following the probe, which started in November and wrapped up in August, Jones said.

The city is cracking down because "bandit" cabs pose a risk to the public, she said.

"You don't know if they're insured, and they wouldn't be insured as a taxicab … you have no control over service issues," Jones said, adding that illegal taxis, which usually charge a flat rate, are typically more expensive than licensed cabs, their drivers are not trained by the city, and customers have no recourse if the drivers choose to drop them off some place they don't want to go.

She urged customers to report such illegal cabs to the city and to use licensed taxis, which are marked, identified with a licence and plate number and have photo identification of the driver posted inside.

Their drivers have all been screened for a criminal record and have received training from the city, she said.

She added that some people may choose to take illegal taxis because some licensed cabs refuse customers who want to go short distances or have been drinking, but the city has been trying to encourage the taxi industry "step up and provide the service" in order to discourage people from calling bandit services.

The city is also increasing the size of the number identifying taxis, and safety measures in licensed taxis such as security cameras, which will be installed in March, Jones said.