As in many tourist areas around the world, a Sustainable Tourism Tax (sometimes called Eco Tax) is imposed by the Balearic Government, collected at the accommodation.
The tax applies to adults only; children under 16 years of age are exempt. The amount has been determined by the local administration and varies between €0.50 and €4 per person per day plus 10% VAT depending on the season and type of accommodation.
The Sustainable Tourism Tax is for the promotion of sustainable tourism and conservation of natural areas on the Balearic Islands. This means you are helping to keep the island beautiful.
Here you'll find more information by the Balearic Government about the purposes of the tax and the projects which are being financed with it.
See this page for the daily rates you will have to pay.