Register an additional dwelling in the Catastro (physical alteration 901N/902N)

What you need

1. Have Cl@ve, certificado digital or DNIe working. If you sign online, install AutoFirma.
2. Works finished and the licencia that allows creation of the dwelling. If your ayuntamiento uses declaración responsable, have that too.
3. If you want an independent referencia catastral, have the división horizontal or the urban title that allows it.

Documentation

• DNI/NIE of the declarant and, if applicable, autorización or power.
• Referencia catastral of the source property.
• Licencia de obra and, if applicable, licencia de primera ocupación or declaración responsable.
• Certificado final de obra and planos acotados with areas per dwelling, signed by a technician.
• Escritura de obra nueva/división horizontal or the document that proves the act.
• Latest recibo del IBI for cross-checking.

Step by step

1. Go to sedecatastro.gob.es and identify yourself.
2. Go to Declaraciones catastrales and choose 901N (new construction/change of use) or 902N (extension, renovation, internal segregation). For an additional dwelling in an existing building it’s usually 902N.
3. Fill in: date of completion of works, description, areas (built/useable), use (residential) and contact details.
4. Attach PDFs: licence, certificado final de obra, planos, escritura/título. Best to include a short technical report explaining the segregation.
5. Sign and submit. Download the justificante.
6. If you prefer in person, book a cita at your Gerencia del Catastro from the sede, print the form and bring originals and copies.
7. Check Carpeta Ciudadana and the sede for requerimientos (they usually give 10 working days). Reply on time.
8. Once you have the resolución, check the Consulta Descriptiva y Gráfica and then verify your IBI with the ayuntamiento.

Expert tips

• If you want independent references, attach the división horizontal with coeficientes. Saves back-and-forth.
• For areas, use the same criteria Catastro uses (built area with and without common parts). Your architect will sort it in 5 minutes.
• If a notary already registered an obra nueva/división, they may have notified Catastro, but don’t assume it: check and declare if it’s not there.
• If the sede won’t let you sign, make sure AutoFirma is updated and try Chrome/Edge. Disable weird blockers.

Common mistakes

• Submitting without the licencia/título habilitante: they’ll stop the file. Always attach the urban backing.
• Not stating the date of completion of works: without it tax effects are unclear.
• Uploading plans without measurements or areas: they’ll request corrections and you’ll lose weeks.
• Waiting for the IBI to “update itself”: if you don’t declare within 2 months, you risk sanción and retroactive adjustments.
• Booking an appointment the day before: some Gerencias have no slots. If you need in person, book early.