Deregister your pet for death, loss or theft (censo municipal)

What you need to have at hand

1. Número de microchip of the animal. Without it you’ll be stuck.
2. Proof of the event: certificado veterinario or crematorium receipt for death; denuncia for loss/theft.
3. DNI/NIE of the holder (and of the presenter if someone else acts, with autorización).
4. PDF forms ready and legible. Avoid blurry photos.

Documentation

1. DNI/NIE del titular (and of the representative if applicable).
2. Tarjeta/justificante del microchip or a vet report with the number.
3. Certificado de defunción/eutanasia issued by the vet or justificante de crematorio (for death).
4. Denuncia policial for extravío/robo with date and description (if applicable).
5. Formulario municipal de baja en el censo (from your ayuntamiento) completed.
6. Autorización firmada and DNI of the holder if someone else files.
7. Cartilla/pasaporte or last vaccination receipt (if the ayuntamiento asks to verify).

Step by step

1. Get the microchip number and the main proof (certificate or denuncia). If you don’t have the chip number, call your vet.
2. Digitise everything to PDF. Group documents by block (ID, chip, proof) and name the files clearly.
3. Go to the sede electrónica de tu ayuntamiento and search “Baja en censo de animales de compañía (fallecimiento/extravío/robo)”. Usually under “Trámites” > “Animales” or “Censo”.
4. Fill the application: holder details, animal data and motivo (fallecimiento, extravío or robo). Put the exact date.
5. Attach the certificate/denuncia, DNI and microchip. If you’re not the holder, attach the autorización.
6. Submit via registro electrónico and download the justificante. If the sede requests Cl@ve or certificado, use it; if a simple form is allowed, that can be quicker.
7. Check the expediente in 24-72 h. If they ask you to subsanar, upload the missing items in the same expediente so you don’t restart deadlines.
8. If your comunidad has a registro autonómico, confirm with the ayuntamiento or your vet and file the baja there too if they don’t do it automatically.

Time-savers

1. Ask the vet to issue the certificate at the time of euthanasia; don’t leave without it.
2. For loss/theft, file the denuncia the same day. It prevents trouble if the chip shows up elsewhere.
3. Reduce PDF size (under 5 MB per file) or the sede may reject uploads.
4. Keep the registro number and a summary of submission. If a fine for “not reporting” comes up, this proves you notified.
5. Add a note in observations if something is missing (e.g., cartilla lost). They’re often understanding if you explain.

Common mistakes that mess up the trámite

1. Not putting the real date of death/loss. In profile checks you can get a requerimiento or sanción.
2. Not attaching the denuncia for extravío/robo. Many won’t process a baja for that reason without it.
3. Mixing up municipal and regional deregistration. Thinking one covers both and later still appearing as “alta”. Verify.
4. Illegible or expired documents. You’ll get a subsanación and lose weeks.
5. Missing the 30 days deadline. Ordenanzas set the plazo; you can be fined even if you regularise later.