According to the national ministry for development, changing the name of Palma airport from Son Sant Joan to Ramon Llull Palma-Mallorca International Airport would cost up to half a million euros.
The Council of Majorca is the prime mover in seeking the name change and it has encouraged the regional government and Palma town hall (plus other town halls) to back the change. The cost of doing so will, if such a change follows the precedents with others, mean that local authorities (possibly with private sector support) have to pay.
The ministry explains that signage and different types of documentation would have to be altered, with the heaviest cost being for substituting the name on the outside of the terminal. There wouldn't be any change to airport operations as such. Aena has experience with previous name changes, which for the most part have an aesthetic impact rather than an administrative one. For the airports authority it wouldn't mean, for instance, changing the code from PMI.
The Council says that it doesn't know how much it would cost to change the name, adding that as the airport is a significant contributor to Aena's financial situation, it should be Aena which pays. In five out of six cases of airport name change, Aena has not contributed, but the case of Adolfo Suárez-Madrid-Barajas was different. The name change was promoted by the Spanish government and not by the local authorities. Although it has been said that the cost of this change amounted to some one million euros and was shared between the Madrid regional government and the city, the cost was more like half this, and it was Aena which paid. The situation was, though, quite different to that of Palma.