Finding the mismatch between the Catastro, the Land Registry and what is built

Terms used

• Nota Simple — The Nota Simple is a short Property Registry extract showing who owns a home.
• escritura — The escritura is the title deed, the notarised document showing who owns a property.

Key rules

• Catastro: A Catastro entry is not proof that a building is licensed or registered.
• Land Registry: Only the Land Registry protects ownership and registered rights.
• Unregistered works: Extensions, pools and closed-in terraces missing from the registered description can block a sale or mortgage.
• Small gaps: Area differences of up to 10% (the legal margin) caused by different counting methods are tolerated.
• Nota simple: Anyone with a legitimate interest can request one, and it has no certifying value.

Start with the three records and your home

The three records are:

• The nota simple: what the Registro de la Propiedad holds about the property.
• The certificación catastral descriptiva y gráfica: what the Catastro holds.
• Your escritura (title deed), if you have it.

Get the nota simple

You do not have to be the owner. You can order it online by card, in person at the registry covering the property, or through a notary or gestor. An online nota simple for one property costs 9 to 10 euros plus VAT, set by the registrars' tariff.

It shows the finca number, location, registered built and usable area, plot area, boundaries, annexes such as parking or storage, owners, and charges such as mortgages or embargoes. It reproduces only what was registered. It does not prove the real building matches, and it does not prove planning legality. It does not show the Catastro reference unless this was entered.

Get the Catastro certificate

Owners can download it free and instantly from the Sede Electrónica del Catastro, using a digital certificate, Cl@ve or electronic DNI. You can also ask for it, free, at a Gerencia or Punto de Información Catastral with ID. A third party needs the owner's authorisation or a legitimate interest. It shows the cadastral reference, address, use, built area, plot area, year of construction, cadastral value, owner and a plan. The Basque Country and Navarra have their own cadastres.

Compare in this order

1. Identity. Check that address, cadastral reference, finca number, owner and annexes agree across the documents.
2. Areas. Compare the built area in the registry, the Catastro and the deed. The Catastro counts some elements differently, such as shares of walls, common areas and terraces, so a gap alone is not proof of a problem.
3. The real home. Measure it, or have a technician do it. Record built area and usable area separately. Note terraces, attics, basements, porches, closed-in terraces, pools, outbuildings, extensions and changes of layout or use.
4. Permits. Compare what you found with the licence, building permit and final-completion certificate, or the declaration of new construction.
5. List the differences. Then decide on the fix: a Catastro update, a registry correction or legalisation.

Differences that matter legally

These need action:

• Extensions, added floors, closed-in terraces, or new buildings such as pools and outbuildings that the declaration of new construction does not cover. The registry cannot reflect them, so the notary requires the proper declaration.
• Work without a licence. It can bring fines and orders to legalise or demolish until the time limit runs out. Your region sets that limit, and the years count from full completion of the works or from when the building could be used. Rural land is treated differently. The ranges are in What if works were done without a permit (obra ilegal)?.
• A change of use without a licence, for example commercial premises used as a home.
• Area gaps above 10% that affect the identity of the property.
• Changes never reported to the Catastro. You file modelo 900D with the Catastro within two months of the licence or the deed. Late or missing reports can bring fines and a back-dated correction of the IBI tax.

To register new works, the registry requires the licence and a technical certificate. For older works, you can register them by age (the antigüedad route): you prove the work is old enough that the council can no longer order it undone, with a certificate of age from a technician or the council, or with cadastral records. That does not apply on protected land.

Differences that do not matter

These need no action: interior finishes, painting, a moved non-structural partition, rounding differences, and an outdated Catastro year of construction or quality category.

What to do next

If your differences are only the harmless kind, you can stop. If any fall under the legal list, get a technician's certificate and ask a notary or the registry which correction route applies. Ask your town hall too, because planning rules differ by region and council.

If you are still abroad or just arriving

Without a Spanish digital ID, you cannot use the online Catastro route yourself. Use a gestor or representative with written authorisation to get the Catastro certificate for you.

You can order the nota simple online by card from abroad. You do not need to travel to the registry.

The apostille, translation and legalisation rules for a foreign document are in Selling or mortgaging a home with irregular work.

Choosing between options

Who should measure and certify what is actually built?

• Architect (arquitecto): Your work is larger or more complex, such as a new build or an extension that involves structure, where an architect must sign the project.

• Building engineer (arquitecto técnico or aparejador): The work is simple housing work or you only need a measured survey and a certificate describing the building; they can sign.

• Surveyor or engineer (topógrafo or ingeniero): You only need plans, area measurements or boundaries, not a certificate of the building.

Acceptance depends on the council and the notary, and some require a professional registered with a professional college. Ask your council and notary first which professional they accept, then choose the simplest one that can sign for your case.

Timeline and deadlines

Online, the nota simple arrives by email as a PDF within 1 working day, sometimes in a few hours. In person at the registry it takes 3 working days.