AT&T said airlines are working “to diagnose and resolve the issue.”
AT&T customers are experiencing a “nationwide issue impacting” their ability to call non-AT&T users, the company said in a statement.
“Carriers are working as quickly as possible to diagnose and resolve the issue,” AT&T said.
The company later said it mistakenly sent a “wireless impact notification” to 9-1-1 call centers during the outage.
“National 9-1-1 services are currently operating normally and our customers are not affected,” AT&T said in a statement around 5:20 p.m. ET.
The Federal Communications Commission said in a post on
Verizon said its network is operating normally, but some users, especially in the Northeast and Midwest, are “experiencing difficulty calling or texting customers served by another carrier.”
This is the second time in three months that AT&T has experienced an outage.
In late February, AT&T customers across the country experienced a similar outage after a software update, the company said.
The February outage temporarily affected 911 services in several states.
The FCC has opened an investigation into that incident.
Elizabeth Schulze of ABC News contributed to this report.