Why is United Airlines upgrading its core reservation system, Shares, this week?

United Airlines is moving forward with a major technology upgrade this week. The carrier will temporarily take its core reservation platform offline. This planned outage is necessary to modernize its aging mainframe system. The goal is to improve long-term operational reliability.

Key Upgrade Details

United is updating its legacy flight reservation system, known as Shares. This system has been the airline's backbone since the Continental merger in 2012. Shares is a highly customized, mission-critical mainframe platform. It manages all flight schedules, seat availability, and passenger records (PNRs).

The upgrade involves a significant data transfer. Reservation data will move from its current data center in North Carolina. It will be relocated to a more advanced, high-tech facility in Chicago.

Timeline and Service Disruption

The service outage is scheduled for early Wednesday, February 4, 2026. The downtime is expected to last approximately four and a half hours. It will begin at 2:30 a.m. EDT and conclude at 6:00 a.m. EDT.

During this window, many customer and employee services will be unavailable. Travelers will be unable to:

• Make new flight reservations.
• Cancel or modify existing bookings.
• Check in for flights via the website or mobile app.
• Retrieve existing itineraries or access MileagePlus accounts.

Impact on Travelers and Mitigation

United Airlines has taken steps to minimize passenger disruption. The airline proactively canceled about 600 flights months ago. These flights were scheduled to depart during the upgrade window.

Travelers with flights on Wednesday morning must plan ahead. The airline strongly urges passengers to complete check-in on Tuesday. This includes checking bags up to four hours before departure. This action will help avoid problems when the system is down.

Operational Reliability and Industry Context

Major reservation system upgrades carry inherent risks. A smooth transition is crucial for operational stability. United has rehearsed the data migration process extensively. Travel experts anticipate a relatively low level of disruption.

However, historical examples show the potential for widespread issues. A computer outage at Southwest Airlines roughly a decade ago caused significant problems. That event led to hundreds of cancellations and thousands of delays over several days. The goal of this upgrade is to prevent similar long-term outages. The move to a new data center aims to boost operational reliability for the future.

This technology investment aligns with United's broader strategy. The airline is expanding its hub at Chicago O'Hare International Airport (ORD). United is also enhancing its technology suite, including tools like Connection Saver.

Modernizing the Shares technology upgrade is a critical step. It supports the airline's long-term growth and customer service goals. The successful completion of this data center migration will provide a more stable foundation. This is vital for a global carrier's complex operations.

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