The Federal Communications Commission voted unanimously Thursday to lower some of the rates incarcerated people and their families pay to speak over the phone. For jurisdictional reasons, the measure only applies to interstate or international calls.

The Commission approved a measure that prohibits companies like Global Tel Link and Pay Tel Communications from charging families and incarcerated people more than 12 cents a minute in large prisons and 14 cents a minute in large jails for out-of-state calls. Previously, rates were capped at 21 cents a minute and single conversations could total several dollars. The action also caps international calling services for the first time.

“Recognizing the exigent circumstances caused by the pandemic, we lower interim interstate rates for prisons and the largest jails,” Acting Chair Jessica Rosenworcel said in a statement Thursday. “This means that interstate rates will fall by more than a third for the vast majority of those who are incarcerated. For the first time ever, we cap international rates.”

For years, criminal justice advocates have fought to reduce the exorbitant costs of phone calls in prisons. The FCC attempted to set similar rules lowering costs for intrastate calls in 2017 but was overturned by a DC Circuit ruling. As a result, its current jurisdiction only applies to calls that cross state or national borders.

A confluence of alleged “monopoly” power and lucrative financial arrangements between prisons and telecom companies are at the root of the expensive phone rates in prisons. In 2015, the Ella Baker Center for Human Rights found that one-third of families go into debt due to high phone rates with incarcerated loved ones.

Lawmakers like Sens. Tammy Duckworth (D-IL) and Rob Portman (R-OH) have introduced legislation that would provide the FCC more authority to lower in-state prison phone rates, but it’s unclear if the bill will be passed.

“There is more we can do. Because as a matter of social justice we are not yet where we need to be,” Rosenworcel said.