N.I.E. is an abbreviation for Número de Identidad de Extranjero, which translates as Identification Number for Foreigners.
The NIE is your all-purpose identification and tax number in Spain. You need it for everything that involves an official process / contracts in Spain. For example, you will need an NIE number to buy a property, get connected to the utilities and, most importantly, pay your taxes. Without an NIE number, the Spanish tax authorities are unable to assess or process annual tax payments such as income tax (IRPF), and the annual wealth tax (Patrimonio), both of which are declared by resident and non-resident property owners.
Who needs an NIE in Spain?
1. Any foreigner who becomes resident for tax purposes in Spain needs an NIE number in Spain.
2. Any non-resident foreigner who buys property in Spain. If a couple buys a property in Spain together, and they register the property in both their names, then both of them must obtain an NIE number in Spain.
3. Anyone who wants to work in Spain, or start a business in Spain.