Could you link to one of the places where you've been told that you'll need it?
NIE (Número de Identidad de Extranjero)
The immigration service issues this number to you once you have made your application in person at your nearest office. This is your identification number in Spain and is needed for any of the following:
Filing taxes
Buying property
Establishing a business
Opening a bank account (and for almost all other forms you fill out).
Both EU citizens and non-EU citizens get issued an NIE.
The NIE consists of an ‘X’ followed by 7 or 8 digits then another letter.
You book the appointment using the first option at this link
https://app.bookitit.com/es/hosteds/...8eae5#services
This link tells you how to fill in the form
https://www.google.com/url?sa=t&rct=...eWf7Hd6GD-QTFf.pdf&usg=AOvVaw2CtTj0UqeWf7Hd6GD-QTFf)
This is the form EX-15 that needs to be completed
+1 for this. That's what I did to get my NIE. It's a bit of a pain to sort an appointment with the consulate (as they were only open some days and odd hours), but you will received the NIE back by email. This is good enough for taxes etc.
You then need to visit the Police Station when you actually start living in Spain to get the official NIE card.
Kind regards
Ian
You don’t need an appointment/shouldn’t try and book one. You can just turn up between 0800 and 1300. You have to fill in the form I linked and another one that takes a couple of minutes and they give you an example one filled in in German.
They take a copy of your passport and you can pay by cash or card.
You will receive a PDF in 3 to 4 weeks.