There is also a NIE questions and answers thread HERE.

To apply for your NIE you need to complete an application form which can be collected from the Police Station in Las Americas or downloaded HERE. (Ignore page 2's notes!).

You will also need to pre-pay 9 Euros before applying for a NIE. For this you will need to get a triplicate modelo from the Police Station and to take it to a bank. When you present the form in the bank and pay your 9 Euros, the bank will retain one of the three copies of the form, and stamp or frank the top copy. This must be taken to the police station along with everything else. If you attend without doing this first you will be sent away. The very first box requires you to insert your NIE number: of course, you won't have this yet! You can either put in someone else's NIE (the Bank's computer system won't know the difference) or you can put in your passport number.

You then take your completed form plus a photocopy and the pre-paid Modelo to the Police Station in Las Americas along with your passport and a photocopy of that. Ignore the section on the application form for attaching photos: you do not need them.

You will need to be at the Police Station early to be guaranteed to be seen, and to be seen without wasting the whole morning. Generally, getting there at 8am should enable you to leave by 10.30. You will be given a numbered ticket outside the entrance to the Police Station at around 9am, and you will then queue in the hall to your right as you enter. When your number appears on the electronic display, you go the desk with your documents. The copy of your application form will be stamped, and it is this that you take back in a few days time to collect the NIE itself. For this, you only need to go to the information desk: you do not need a number, nor to arrive before 9am.

The form needs to be completed in Spanish.

1er Apellido … Surname (ignore 2º Apellido … Second surname (unless you have one)
Nombre … First Name
Fecha de nacimiento … Date of Birth
Lugar de nacimiento … Place of birth
Sexo … Sex (H = MALE. M = FEMALE)
Estado civil … S = single; C = married; V = widowed; D = divorced
Pais de nacimiento … Country of birth
Pais de nacionalidad … Nationality eg British
Nombre del padre … Fathers name
Nombre de la madre … Mothers name
Domicilio en España … Address in Spain
No … apartment/house number
Piso … floor number (if applicable)
Tel … Telephone number
Localidad … Municipallity eg Arona, Adeje etc
CP … Postcode (5 numbers long)
Provincia … Province.... this is Santa Cruz de Tenerife

The place you are applying is España, and in MOTIVO POR EL QUE SOLICITA EL N.I.E. put a cross in Social (this is the most usual reason, after all, and does not involve any further bureaucracy with Social Security or the Hacienda).

If you are collecting your NIE certificate yourself there is no problem: you will just need your stamped application form copy and your passport. If someone is collecting for you, however, then you need to put their details in Datos del representante legal. Put in their name and NIE number. They will need to provide proof of identity when they collect your NIE.

At the bottom of the application form is a place for you to put your address for notifications: applicants would normally just put in their Spanish address in the same form as they entered it the first time.

You need to sign at the bottom, and also sign under the details of the person who will be collecting for you, if applicable.