T-Mobile was affected by a network outage that hampered texting and calling on Monday.
On social media and the site Downdetector, T-Mobile (TMUS) - Get Report customers in the U.S. reported problems with sending and receiving calls. The reports appear to have peaked at around noon Pacific time.
Shares of T-Mobile fell 1.2% in after-hours trading on Monday.
In a statement on Twitter, T-Mobile's president of technology Neville Ray apologized for the inconvenience, but didn't offer an explanation for the outage.
The outage appears to have started around 9AM PT, and continued into the afternoon. In total, hundreds of thousands of reports were filed with the site Downdetector, which tracks outages of cell networks, popular websites and other heavily-used services.
By mid-afternoon PT, numerous unhappy customers had replied asking for account credits or other restitution for the outage, which they said had prevented them from making work calls.
Representatives from AT&T and Verizon confirmed to press outlets that their networks were running normally on Monday.
In its latest earnings release, T-Mobile beat earnings estimates but pulled its second quarter guidance owing to the uncertain impact of COVID-19 on its financial results.
T-Mobile closed its $23 billion merger with Sprint at the beginning of April, and will report combined results with Sprint starting this quarter.
Shares of T-Mobile are up 33% year to date.