See:
http://www.vueling.com/info/conditions.php?language=EN#7
8.5 Baggage weight per passenger: Each passenger can transport in the hold (according to luggage allowance) up to a maximum of 20kg of luggage, for which they must pay the corresponding fee (€10 per flight and suitcase when this service is contracted through our website, and €20 per flight and suitcase when it is contracted in the airport). The passenger must pay €8 per kg of luggage that exceeds the 20kg limit mentioned above. The carrier reserves the right to increase, reduce or annul these amounts at any time. The carrier may refuse to transport the totality or a part of the luggage that exceeds the weight stipulated in clause 8.5, or which has not been previously paid for.
