Nie number
If you are planning moving to Spain or buying a property in Spain, first of all, you have to sollicit a NIE, spanish identity number (identity number for foreigners).
The NIE number should be obtained in the nearest Police Station (Police headquarters). If you are plannig buying in the area of the Delta del Ebro, you have to sollicit the NIE at the Police Station of Tortosa and if you are planning buying in the area of Castellón, you have to sollicit it at the Police Station of Castellón
How to get the NIE number
To sollicit in person the NIE in Spain is a relatively straightforward processus. The unique disadvantage is that you risk to queue a several hours to deliver the solicitude for the NIE. That depends evidently on which Police Station you have to go and on which hour (preferently on the morning). With good luck, you can go in and out in a half-hour or less.
Necessary documents:
Collect NIE after 30 days
After you have submitted your NIE application you will be given an official receipt (resguardo). Unless you are told otherwise you will be able to collect your NIE from the office where you made your application anytime from 15 days later. You do not have to collect your NIE in person - anyone can collect it for you if they have the official receipt you were given when you submitted your application.