Yes. You can check in up to 9 people at one time online, even if they are not on the same booking. For those on a different booking, click on "add another passenger" when selecting passengers to check in, and enter the electronic ticket number.
Can I choose my seat if I use my mobile phone to check in?
You can confirm or modify your seat preference by accessing our cabin layout tool when checking in via your mobile phone. If you have purchased a Mini price ticket, seat selection is only available at the airport at a Self-Service Kiosk or at the check-in counter.
Some countries require that international airline companies transmit all or part of their passengers' personal information. At check-in, you will be asked to complete a form. In addition to the standard information (nationality, name, date of birth, passport number, etc.), you must also indicate the address at which you will be staying while in the United States.