The "Virgin" carry-on luggage allowance depends on whether you are flying with Virgin Atlantic or Virgin Australia, and your class of service. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) In general, all Virgin flights include one personal item that must fit under the seat in front of you, like a handbag or laptop bag. 

Virgin Atlantic carry-on allowance

• Economy and Premium Economy: 1 piece of hand luggage weighing up to 10kg (22lbs).
• Upper Class: 2 pieces of hand luggage with a combined weight up to 16kg (35lbs), with no single bag weighing more than 12kg (26lbs).
• The maximum dimensions for all hand luggage is 56 x 36 x 23 cm (approximately 22 x 14 x 9 inches). Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK).