British Airways` flights continue to be affected today (Sunday, June 18) following the Air Traffic Control computer failure on Saturday June 17.
Twenty domestic and European flights have been cancelled today, with other short haul flights delayed.
Long haul services from Heathrow and Gatwick are operating to schedule.
The airline is doing everything possible to get customers to their destinations as quickly as possible.
Extra staff have been drafted in to offer help and advice to people affected by the disruption.
Customers are being offered full refunds or the option to rebook. This applies to everyone, including those people whose tickets would not normally allow for refunds or booking changes.
A special flight information line for customers has been set up. The number is 0870 6000969.
The airline is recommending that customers call this number before leaving for the airport.