The CEO of AT&T on Sunday apologized for the widespread cellular outage that knocked out service for thousands of customers, saying some accounts will receive credits to compensate for the incident. 

“For the portion of consumer and small business customers most impacted by the outage, we are automatically applying an account credit to compensate them for the inconvenience they experienced,” Chief Executive John Stankey wrote in a letter to employees. 

“We all know that our customers receive tremendous value and convenience for the nominal daily cost of our service, and outages sometimes have outsized impacts on some subscribers that may be greater than the face value of the credit. For that reason, I believe that crediting those customers for essentially a full day of service is the right thing to do,” he continued. “Despite that impact to the business, I believe this approach is fully manageable while achieving the 2024 business objectives we have set for ourselves and our stated financial guidance.” 

Impacted customers who prepay for their service will have “options” available to them and the company is working with its mid-market and enterprise customers to address their concerns, Stankey said. 

Early Thursday, tens of thousands of AT&T customers across the U.S. reported widespread service outages and were unable to use their phones without access to WiFi. A spike in outages began around 4 a.m. ET and peaked at around 74,000 reported incidents at 8:30 a.m. ET, according to Downdetector.

The outage raised concerns that the company had potentially been hit with a cyberattack but an initial review of the incident found it was caused by “the application and execution of an incorrect process used while working to expand our network,” Stankey said. 

“Teams worked hard to successfully normalize the network by around noon CT. No matter the timing, one thing is clear — we let down many of our customers, including many of you and your families. For that, we apologize,” he said. “These challenges provide opportunities to identify key learnings that will make us better, and I can tell you that we have already implemented changes to prevent what happened on Thursday.”

Once the company realized there was an outage, it prioritized restoring service to first responders and reconnected remaining customers throughout the day. Stankey thanked staff for their efforts in handling customer complaints, communicating information about the outage and restoring service.