Companies rarely invoke mandatory arbitration clauses to prevent individual customers from going to court, but they are frequently used to prevent class action lawsuits, the Consumer Financial Protection Bureau said Tuesday.

Companies used the clauses to stop class actions 65 percent of the time in consumer financial contracts, including those tied to credit cards, reloadable prepaid cards, private student loans, storefront payday loans and wireless phones, according to a study by the bureau.

The study also found that in cases where consumers win class action and individual lawsuits, the awards are on average small.

Plaintiffs on average were awarded $137.50 in class action consumer finance settlements from 2008 to 2012, according to the study.

The 3,500 consumers who filed individual lawsuits obtained just a total of $1 million from 2010 to 2012.

Three out of four consumers don’t know if they are subject to the mandatory arbitration clauses, according to the study.

CFPB Director Richard Cordray noted that mandatory arbitration clauses in consumer financial contracts have only become common in the last 20 years.

About 80 million credit card holders are subject to mandatory arbitration clauses, which limit their ability to go to court to settle grievances.

Nearly all large private student lenders and third-party wireless phone vendors use the clauses.

While the clauses generally prohibit consumers from litigating the disputes, most allow the customers to go to small claims courts to settle the matters.