legalising renting a house to holiday people

[Lavanda]

Over the past few years we have rented out our town house for a few weeks every year to paying holiday guests who are not family or people we knew (as in 'knew before they rented our house'). I did inform the insurance people and they weren't bothered but I've been thinking of legalising the situation with a view to advertising the house and renting it out for a few more weeks each year.

I've sought advice from the Ayuntamiento and it seems my choice is to carry on as I am or go down the Casa Rural route and pay Autonomos. The Autonomos route is not very appealing as I'm retired and the cost of the Autonomos will be greater each year than the holiday rental income which is currently about €1500.

Any ideas?