By Megan Cerullo
Feb. 2, 2026 / 6:56 PM EST / CBS News
United Airlines will take its online reservation system offline during a planned technology upgrade early Wednesday, asking customers with Wednesday flights to check in on Tuesday to avoid issues. The carrier says the outage will last about four and a half hours, from 2:30 a.m. EDT to 6 a.m. EDT.
An alert on United’s homepage says the airline is “conducting a planned technology upgrade” and warns that many web and mobile app services will be unavailable during the maintenance window, including tools used by employees.
The work modernizes United’s decades-old mainframe reservation system, Shares, and involves moving reservation data from its current North Carolina data center to a more advanced facility in Chicago. United says the transfer should improve system reliability.
What passengers should do
During the outage customers will not be able to make new reservations, cancel bookings, check in, retrieve itineraries or access many online services. United urges anyone traveling Wednesday to check in on Tuesday and, if necessary, check bags then — passengers can typically check bags up to four hours before departure.
The migration has been planned for months; United previously canceled roughly 600 affected flights and notified customers. Travelers can still book, check in or change trips before the outage begins at 2:30 a.m. EDT, or after the data transfer is finished.
Risks and expectations
United says it has rehearsed the migration and expects the transfer to go smoothly. Travel experts also predict limited disruption. “Don’t freak out if you can’t search for flights in the middle of the night,” Scott Keyes, founder and CEO of flight-deals site Going.com, told CBS News. “It will come back online soon.”
Still, the airline acknowledges that if the upgrade runs into problems it could create customer headaches. A decade ago, a major computer outage at Southwest Airlines lasted days and led to hundreds of cancellations and thousands of delays.
Edited by Alain Sherter
Kris Van Cleave contributed to this report.