LOS ANGELES, Calif.–A class action lawsuit against Los Angeles for a refund of potentially hundreds of millions of dollars in telephone taxes may proceed following a unanimous ruling by the California Supreme Court.

Monday’s ruling, written by Justice Ming W. Chin, upheld the right of citizens to bring class actions against municipal governments for collection of allegedly illegal taxes.

The decision will affect similar lawsuits against Los Angeles County, Long Beach and Chula Vista, lawyers in the case said in remarks reported by the Los Angeles Times. The suits claim that the governments have illegally taxed telephone users.

The case against Los Angeles was filed in 2006. The city argued that the taxpayers should have filed individual claims for refunds before bringing a class action and won in the trial court and the appeals court.

But as a result of Monday’s ruling, “It’s possible we will consider bringing actions against other jurisdictions,” Frank Gregorek, who argued the case for the taxpayer, told The Times. The class that would recover funds would include all residents who paid the taxes.

During the years at issue, Los Angeles charged users a 10 percent tax on their phone bills, he said.

City voters later approved the tax but lowered it to 8 percent. The city did not immediately respond.