The Spanish city with the 'most illegal' holiday homes - not in Costa del Sol

With its flamenco, culinary excellence, and the largest Gothic cathedral in the world, Seville is a hot tourist destination - and not just because of the weather. With more than three million tourists a year and a population of 700,000, it is the third most visited city in Spain. But as with all things, mass tourism comes with its problems, and illegal tourist flats certainly add to the pile. According to data published by the Ministry of Housing and Urban Agenda, Seville is the city in Spain home to the highest number of tourist apartments operating outside legal regulations, with 2,289 units. Following Seville, Marbella saw 1,802, Barcelona 1,564 and Malaga 1,471 units, The Olive Press reports.

Running since July 1, 2025, the single rental registry is a nationwide system created to identify and verify all properties intended for temporary rentals in Spain. The measure aims to curb illegal short-term rentals, improve the housing crisis, and ensure tourist safety. If a property is not on the register, it cannot legally be advertised online.

This comes as a significant number of properties in Spain are being rented out to tourists without proper registration or licenses. To deal with the issue, prime minister Pedro Sánchez announced earlier this month that thousands of illegal tourist flats will be transformed into permanent housing for residents.

Sánchez wrote on X: "We will demand that platforms remove 53,000 tourist flats for failing to comply with regulations. So that they can become permanent rentals for young people and families in this country."

Platforms such as Airbnb and Booking.com have been asked to remove adverts for rule-breaking properties by the Spanish housing ministry. However, Airbnb and the Spanish Ministry of Housing identified that less than 10 per cent of the listings that were turned down by the registry were on Airbnb.

An Airbnb spokesperson said: "The vast majority of non-compliant listings are not on Airbnb. So we are calling on other platforms to join Airbnb's ongoing enforcement effort with local authorities."

Last summer, Seville's city council pledged to crack down on the surge of illegal tourist rentals by cutting off the water supply to apartments operating without a licence. Three property owners appealed the decision, but the courts ruled the council's actions were lawful. Meanwhile, in Barcelona, Mayor Jaume Collboni revealed plans to effectively phase out tourist apartments by 2028, refusing to renew the licences of more than 10,000 legally registered flats.

Residents in Spain's tourist hotspots blame the boom in short-term rentals, legal and illegal, for the housing crisis, with many forced to leave due to soaring costs. Rents have risen 80% over the past decade, outpacing wages, and nearly half of tenants now spend at least 40% of their income on rent and utilities - well above the EU average of 27%.