http://www.britishairways.com/en-us/...on/checking-in
Check-in times
You can check in online or on your mobile phone, from 24 hours and up to 1 hour, before your flight is scheduled to depart.
•To find out check-in times at the airport, go to Manage My Booking. Click on your flight number, select ‘Check in’ and then click on ‘Other ways to check in’.
•Check-in close times:
London Heathrow - all flights 45 minutes before departure
London Gatwick - all flights 45 minutes before departure
London City - all flights 20 minutes before departure
London Stansted - all flights 45 minutes before departure
UK domestic airports - 45 minutes before departure
Short haul European airports - 45 minutes before departure, except Lisbon (50) and Madrid (55)
Long haul international airports - at least 60 minutes before departure, check Manage My Booking
OpenSkies flights from Orly - 50 minutes before departure
•You need have your boarding pass before check-in closes or we will be unable to accept you for your flight.