Rental Licence for Murcia region

[costa-brava]

Answer to Xibalba
Yes there is an enormous difference but like I said it is not standard throughout the regions.
The law in Spain was always that a Vivienda/Dwelling house or apartment could be rented as such for any period of time whatever. That ended last year in June when the Spanish government passed a new law on housing that excluded short term holiday renting from the standard "vivienda" classification. With just a couple of lines in an appendix to the law they pushed the responsibility for holiday rents out to the regional governments. Some, like Catalonia, Ballearics etc, already had some provisions in place.
But the bottom line is that if you rent out for more than 31 days or 90 days (depending on the region) you are not classified as tourist accommodation so you do not need any type of license.
However, you must declare the income; you must have all the basic certificates (habitation, energy efficiency, ownership) ; you must issue a contract with each let. If you rent out longer term you may be entitled to tax allowances because you are considered to be helping the shortage of rental accommodation.
Although people talk about the big hotel "lobbys" this shortage of housing is part of the reason that some regions prohibit holiday renting.
The last (but important) aspect of medium/long term renting is that you can have problems if you advertise in a holiday lettings site. In some areas the owners ask holiday renters to sign a contract for 3 months, supposedly to get around the law, but the authorities are aware of this.