If you have already booked:

Seat upgrades can often be arranged directly on the airline’s website. Visit the airline’s site and use your airline booking reference (found on your flight voucher) to view available upgrade options.

If you have not yet booked:

During the booking process on our website, click ‘See All Flight Options’ and filter by fare class. Any available upgraded flights will be displayed for you to review and select. The total additional cost will be shown, this reflects the full amount, not per person.