c6ba58cf_int_Business___British_Airways__Customer_Classification
[Definition] Indulge yourself before departure in a wider range of airport lounges when you fly First Class or Business Class with any oneworld member airline. Customers flying First or Business Class have access to the equivalent class of lounge regardless of their frequent flyer status. First Class passengers may use a Business Class or frequent flyer lounge if a First Class lounge is not available. First Class passengers may invite one guest to join them in the lounge. The guest must also be traveling on a flight operated and marketed by a oneworld airline. Connecting between oneworld marketed and operated flights: First and Business Class customers connecting on the same day of travel, or before 6am the following day, can access the lounge when traveling between an international long haul* and an international short haul or domestic flight (and vice-versa). (* a oneworld international long haul flight is defined as an international flight marketed and operated by any oneworld carrier with a scheduled flight time longer than 5 hours) Lounge access will be determined on the international long haul ticketed flight (either First of Business Class) regardless of the ticketed class of travel on the international short haul or domestic flight. You must be prepared to show your boarding pass or itinerary showing travel in First or Business class on the international long haul flight, in order to access the lounge before your international short haul or domestic flight. The following exception applies: First and Business Class customers who do not hold Emerald or Sapphire tier status are not eligible to access American Airlines lounges when traveling on solely domestic flights within the U.S. or between the U.S. and Canada, Mexico [except Mexico City], the Bahamas, Bermuda and the Caribbean) other than the exception listed below: Customers traveling in First or Business class on U.S. transcontinental flights between JFK-LAX, JFK-SFO and MIA-LAX (and vice-versa) are eligible for lounge access. [Customer Classification] 
oneworld® Lounge Access for First Class or Business Class Customers
Joint Business - British Airways
Customer Classification