The suit against some of the country's biggest wireless carriers, including Rogers, Telus and Bell Mobility, was launched in 2004.
The companies appealed the certification of the suit all the way to the Supreme Court, which today dismissed the appeal — paving the way for it to proceed.
As is customary, the high court did not provide reasons for its decision.
The suit alleges the cellphone companies wrongfully collected the fees from customers, which were in addition to other monthly fees for phone service.
It calls for the respondents to be reimbursed.
The lawsuit claims that monthly "system access fees" were created in response to annual fees charged by the government.
However, "these fees amount to less than 20 per cent of the additional charges being charged to their customers under the guise of government taxes," the claim says.
The access fee charge, typically $6.95, "bears no relation to any actual cost of providing wireless or cellular services, but was an amount selected ... by the defendants to proliferate the misrepresentation (that) ... charges were being collected as a tax on behalf of a government agency."
The allegations have not been tested in court.
"We appealed this because we believe the case was not properly presented to the courts as a class action," Telus said in a statement.
"The appeal was a procedural process, and there's been no finding on the merits of the case itself. We are confident the case is without merit and baseless, at least as it related to Telus."
Bell declined to comment.
In an email, Rogers said it appealed all the way to the high court because "we think there are compelling issues that are worthy of consideration by the Supreme Court of Canada."
"We’re confident this claim is unfounded and now look forward to having our day in court on the merits of this claim," Rogers added.
While some cellphone companies have phased out system access fees, the suit seeks to recoup fees paid reaching back two decades.
The class action was certified by the courts in Saskatchewan in 2007.