In Spain, there is a local record for people residing in a town. This local record is called Padrón and the proof that you are registered and residing in a town is the Certificado de Empadronamiento.
If you are told that you need to “empadronarte” this means that you have to register yourself in the Padrón (the local resident record).
You only need to register in the Padrón if you reside in Spain. If you only own a holiday property you don’t have to register yourself as a resident in a certain town.
The Padrón is a proof of residence that allows you to register for the Spanish public healthcare, to vote on the local elections, to enroll your children in a Spanish public school or to get Spanish plates for your car.
For registering you need to go to the Padrón Office in your town or the local Town Hall. The authorities will ask you for your passport, NIE number, copy of your Title Deeds (Escritura) or copy of Rental Contract and a recent utility bill. Some towns will ask you to pay a small tax for registering on the Padrón.
This process is pretty fast and normally you get your certificate right after you register.
The certificate expires in 3 months, so if you ever need a new certificate you just have to go to the Padrón Office or Town Hall to get a new one.