How Barcelona's Housing Crackdown Exposed a Digital Mess: The Story Behind the Duplicate Listing Problem

Barcelona's housing enforcement office has been quietly wrestling with a problem that predates the current rental crisis by nearly a decade: thousands of property listings in the city's short-term rental registry carry duplicate or recycled images, making it nearly impossible for inspectors to confirm whether a given flat in Eixample or Gràcia is the same property listed under two different licence numbers. The issue came into sharp focus this spring when the Ajuntament de Barcelona began the latest phase of its campaign to eliminate unlicensed tourist apartments across the city.

The timing matters. Mayor Jaume Collboni has staked significant political capital on reducing the city's roughly 10,000 licensed tourist apartments to zero by November 2028, the date when the last tranche of existing licences expires under the city's current plan. Enforcing that deadline requires clean data. Duplicate images in the registry — the same living room photograph appearing under three different addresses on Carrer de Provença, for instance — give bad-faith operators an easy defence when inspectors arrive at the door.

How the Duplication Built Up

The problem has deep roots. Between 2015 and 2020, Barcelona's short-term rental sector expanded rapidly across Airbnb, Booking.com and a constellation of smaller platforms. Landlords and management companies routinely repurposed the same stock photographs across multiple listings, and in some cases across multiple properties. When the city's Habitatge Metropolità registry cross-referenced platform listings against its own licence database, it inherited that contamination. A 2023 audit by the Institut Municipal d'Hisenda — the city's municipal finance body — flagged the image-duplication issue as a secondary finding during a broader review of tax compliance among short-term rental operators, according to documentation reviewed by The Daily Barcelona.

The city's existing inspection tools were built for a different task: checking whether a licence number displayed on a platform listing matched an active registration. They were not designed to do reverse image searches across tens of thousands of records. That gap meant inspectors from the Servei d'Inspecció i Control de l'Habitatge, the unit responsible for on-the-ground enforcement in neighbourhoods from Sant Pere to Nou Barris, spent hours manually cross-referencing addresses that should have taken minutes.

What the City Is Doing Now

Since January 2026, the Ajuntament has been piloting a new data-matching protocol developed with support from the Barcelona Urban Lab — a public-private innovation space based in the 22@ technology district in Poblenou. The protocol uses perceptual hashing, a technique that generates a fingerprint from an image's visual content rather than its file name or metadata, to flag listings that share near-identical photographs. Early results from the pilot, covering roughly 4,200 active licences in the Ciutat Vella and Sant Martí districts, identified more than 340 suspected duplicate image clusters requiring manual review, according to figures shared by the urban lab at a May 2026 conference on housing data governance.

The tourist tax expansion announced last year — which raised the nightly surcharge on tourist apartments to €4 per person from November 2025 — has added financial urgency to the clean-up. Every licence that exists only as a digital ghost in the registry represents a potential gap in tax collection. The Agència Tributària de Catalunya, which administers the regional tourism tax, has a direct interest in the outcome.

Operators who believe their listing has been incorrectly flagged as a duplicate have until 30 September 2026 to submit a formal challenge through the Oficina de l'Habitatge closest to their property — there are 10 across the city, including the busy office on Carrer de la Llacuna in Poblenou and the one serving Gràcia on Carrer de Torrent de l'Olla. Those who miss that window risk having their licence suspended pending a longer administrative review. For the thousands of residents waiting for tourist apartments to convert back to residential use, the unglamorous work of cleaning up a database is, in the end, what stands between the policy and the reality.