Airbnb in Barcelona

I don't really know. But we are staying in Barcelona in an airbnb right now. So it is not currently a problem. As to the future, I can't really say.

Apartments for short lettings (a.k.a. tourist apartments) need to be registered in a special registry and have a registry number assigned -called HUT (Habitatges d'Ús Turístic), sometimes also HUTB. This registry number ensures that the proprietors are paying taxes and it also ensures a certain degree of protection for you in the case of problems -should you have to place a formal complaint, for any reason.

The registry is available here: http://www14.gencat.cat/rtcwebguies/AppJava/cercaEstabliments.do?pst=6&lg=en

It's compulsory that all advertisements of tourist apartments provide this HUT number. All actors -including intermediaries like Airbnb, Homeaway and a few other portals- were given plenty of time (over two years!) to ensure they complied with the new laws. Some did, but others chose not too -including Airbnb among others- so the Catalan government has started to issue fines to force everybody to comply and the Barcelona City Hall has started to crack on illegal apartments -those that have not registered: http://ccaa.elpais.com/ccaa/2016/06/28/catalunya/1467113096_156651.html

While at the beginning the City Hall tried not to close down apartments until their occupants had left, now it's not the case and there have been a handful of cases in which the companies that rented the illegal apartments (=not legally registered) have been fined and forced to find another accommodation for their clients in a rush because their original apartment has been closed.

Rule of law... simple as that.

Btw, this law embraces the whole of Catalonia, not just its capital city Barcelona. So you know.

And just a little more to back up Enric's post:

https://www.thelocal.es/20160629/barcelona-to-raise-fine-for-illegal-home-rental-lodgings-to-600000