How Barcelona's Rental Market Became Flooded With Duplicate Listings — And Why That's About to Change

Barcelona's housing enforcement office has been sitting on a problem that predates the pandemic, predates the tourist tax, and predates Mayor Jaume Collboni's crackdown on short-term rentals: the systematic duplication of property listings across digital platforms. A single apartment in Gràcia might appear on Airbnb, Booking.com, Vrbo, and a local agency portal simultaneously, under different names, different photos, and sometimes different prices — making it nearly impossible for inspectors to track illegal lets or enforce the city's 2014 cap on tourist apartment licences.

The issue matters now because Collboni's administration has staked a significant part of its housing agenda on digital enforcement. The city has publicly committed to phasing out all 10,101 active tourist apartment licences by November 2028, when existing permits expire. That is a hard deadline, and the infrastructure needed to actually enforce it — including de-duplicated, cross-referenced listing databases — does not yet fully exist.

How the Database Mess Accumulated

The roots of the problem go back to 2012, when the Generalitat de Catalunya first required tourist apartments to register under the Habitatges d'Ús Turístic scheme and display a registration number. The rule existed on paper. Enforcement lagged. Platforms operating in Barcelona were under no legal obligation to verify that registration numbers were unique, valid, or even real. A landlord with one licensed flat on Carrer de Provença could list it multiple times with cosmetic variations — different crop on the same photo, slightly altered description, new listing name — effectively gaming search algorithms to generate more bookings.

By 2019, the urban planning research group at the Universitat Politècnica de Catalunya had documented significant overlap in listing data scraped from major platforms in the Eixample and Sant Pere, Santa Caterina i la Ribera neighbourhoods. Duplicate and near-duplicate listings inflated the apparent supply of tourist accommodation, distorted pricing signals, and made it harder for the Ajuntament de Barcelona's inspection teams to match listings to physical addresses and valid licences.

The pandemic briefly collapsed the short-term rental market in 2020 and 2021, but it did not clean up the databases. When demand returned in 2022 and 2023, the duplicate problem came back with it, compounded by new micro-platforms and Spanish-language rental portals that had launched during the quiet years.

What the City Is Now Trying to Do About It

The Ajuntament's approach has two tracks. The first is legal: Barcelona was among the first Spanish cities to invoke the EU's Short-Term Rental Regulation, which came into force across member states in May 2025 and requires platforms to share listing data with national and local authorities in a standardised format. Under that regulation, a single registration number can only be associated with one active listing per platform — a technical rule that, if enforced, should mechanically eliminate most duplicates.

The second track is administrative. The city's Oficina de l'Habitatge, which has branch offices across the city including locations in Sant Andreu and Les Corts, has been cross-referencing platform data against the Generalitat's HUT registry since late 2024. The process is manual and slow. The office identified several hundred listings in the Poblenou and Barceloneta areas alone that carried either invalid or recycled registration numbers — a signal of either duplication or outright unlicensed operation.

For renters navigating this market, the practical implication is straightforward: if a listing lacks a visible, verifiable Número de Registre de Turisme de Catalunya — a string beginning with HT-followed by a location code — the accommodation is either unlicensed or the listing is a duplicate of one that is. Reporting suspect listings directly to the Ajuntament via the 010 municipal helpline is the fastest route to triggering an inspection. The city's goal is a clean, de-duplicated database of all active tourist lets by the time the 2028 licence expiry arrives. Whether the technical and administrative machinery is ready in time is the question officials will be answering for the next two years.