AT&T has won an important round in its ongoing battle to end traditional landline service for 184,000 California households, including many that rely on copper-wire phones as an essential connection during natural disasters such as fires, storms, and earthquakes.

The win came in a June 29 decision from the Federal Communications Commission, which contradicted a 2024 mandate from the California Public Utilities Commission that ordered AT&T to continue service.

Despite the F.C.C. ruling, the matter is far from resolved. Both sides are battling each other in two separate courts in what has become a test of state versus federal power.

The F.C.C. opened the door to AT&T’s challenge when it issued a ruling in April that asserted its decisions would prevail over state public utilities commission rulings when the two were in conflict.

At AT&T’s request, the commission subsequently intervened in an area that is typically regulated by the states: deciding whether a phone company can abandon its duties as a “carrier of last resort,” or COLR.

Companies with COLR status are required to offer basic phone service to anyone in their service area who requests it, regardless of how much it costs to provide it. In rural areas, the copper-wire phone service that COLR providers offer is a lifeline, ensuring universal access to phone service.

In its arguments to the C.P.U.C., AT&T said that copper landlines were outmoded and too expensive to maintain. It asserted that alternatives like cell service and internet phones could provide reliable coverage. 

But a coalition of consumer groups, including The Utility Reform Network, argued that landlines are essential in the many rural areas where cell service is spotty or nonexistent. Those groups are supporting a TURN challenge to the F.C.C.’s rulings in the United States Court of Appeals for the Sixth Circuit. 

Meanwhile, AT&T is challenging the C.P.U.C.’s 2024 ruling in the U.S. District Court in San Diego.

Ryan Johnston, an attorney for TURN, said the F.C.C.’s intervention into the California case was highly unusual. 

“The F.C.C. is stepping into an arena that has historically been regulated by the state,” he said. “They are essentially looking to hand AT&T a fairly large gift at the expense of the consumers.”

Harriet Barlow, a Point Reyes Station resident with spotty cell phone service, is watching the legal saga with interest. She and her late husband, David Morris, were among many rural residents who lobbied the C.P.U.C. two years ago, beseeching commissioners to deny AT&T’s request to abandon landlines.

She noted that AT&T has also been lobbying the California legislature to pass a bill allowing it to shed its COLR responsibilities.

“They’re like octopuses in this regard,” she said. “They have many different arms. It’s important to remember that they’ve been doing this all over the country. Poor little Marin isn’t their sole victim.”

The company has already ended its landline service in states with less stringent COLR rules. And it has already begun sending letters to some California customers, informing them that their landline service will end in June 2027. 

The company intends to close 360 “wire centers” that covered areas of differing size, and their boundaries don’t overlap precisely with cities or zip codes.

“There aren’t too many people who won’t be affected,” Mr. Johnston said. “They are looking to cease operation of all of their landline service in California.”