Declare an additional dwelling in Catastro (you created another dwelling in your property)

What you need at hand

• Cl@ve, certificado digital or DNIe. Without this, you’ll need a cita at the Gerencia.
• Referencia catastral of the original property (on IBI receipts or in the Sede).
• Actual date of end of works (from the certificado final de obra).
• How it ended up: number of final dwellings and surfaces per floor.

Documentation

• DNI/NIE of the owner. If you represent someone: autorización and the represented person’s DNI, or an apoderamiento.
• Licencia de obras or declaración responsable and certificado final de obra.
• Cédula de habitabilidad or licencia de primera ocupación (if applicable in your CCAA/ayuntamiento).
• Planos acotados current with layout and surfaces (legible PDF). If available, proyecto or memoria.
• Escritura or nota simple. If there’s división horizontal, its escritura and shares.
• Referencia catastral and contact details (phone and email).

Step by step

1. Go to https://www.sedecatastro.gob.es and check your referencia catastral.
2. Log in with Cl@ve/certificado to Declaraciones, comunicaciones y solicitudes (DCS). Choose the vivienda adicional procedure (physical alteration that creates another dwelling).
3. Enter fecha fin de obra, a description of the reform, number of resulting dwellings and surfaces. Attach licencia/declaración responsable, certificado final de obra, planos and habitabilidad/primera ocupación.
4. Add all holders. If you act for someone else, attach autorización or select the apoderamiento. Review and register the application. Download the justificante.
5. If you go in person, book a cita at your Gerencia del Catastro and present the same documents at the Registro. Note: plazo 2 meses from end of works.
6. Monitor Mis expedientes in the Sede. If there’s a requerimiento, answer within 10 días hábiles by uploading what they ask.
7. When resolved, check the number of dwellings, surfaces and referencias. Review your IBI for possible charges.

Tricks that save time

• Upload clear PDFs, not blurry photos. Split into files <10 MB and avoid tildes in filenames.
• Add a before/after plan and a short memoria explaining accesses and the kitchen. This avoids requerimientos.
• If you don’t yet have habitabilidad, submit anyway and state you’ll provide it. Better to be in time and then subsanar than be out of plazo.
• If there are multiple holders, get all signatures/authorizations beforehand. That’s a common delay.

Typical mistakes that can mess up the process

• Declaring when there isn’t an independent dwelling (no kitchen or no separate access). They’ll reject it.
• Missing the 2 months deadline: possible sanción and retroactive IBI.
• Uploading plans without measured surfaces. Expect a requerimiento.
• Forgetting co-owners or not proving representation. The case stalls.
• Trusting that “the ayuntamiento will submit it”. Sometimes they take months: then the complementarias arrive and it’s unpleasant.