A job offer arrives. The contract looks good. Then the employer asks for something called a NUSS.
Most people have never heard of it. What follows is a rushed search through government websites, contradictory information about where to get it, and the slow realization that the next available appointment might be weeks away. The employer needs an answer by Friday.
The contract goes to someone else.
This happens constantly across Spain — not because the process is difficult, but because nobody explains this number exists until the worst possible moment. And here's what makes it frustrating: for someone with digital identification, the entire process takes less time than making coffee. For everyone else, it can stretch into weeks of waiting.
The difference isn't complexity. It's preparation.
What Is the Spanish Social Security Number (NUSS)?
Spanish bureaucracy uses two terms for the same thing, which causes unnecessary confusion.
NUSS (Número de la Seguridad Social) refers to the number when assigned before employment — to students, healthcare applicants, or people registering proactively. NAF (Número de Afiliación) is technically what the same number becomes once work begins.
Same twelve digits. Different administrative label. In practice, employers simply ask for "the Social Security Number" and don't care which acronym applies.
The number is unique, permanent, and lifelong. Once assigned, it follows a person through every job, unemployment period, and retirement in Spain. Losing track of it doesn't mean losing it — the number remains in the system forever.
This creates an important distinction most guides overlook: people who worked in Spain years ago, even briefly, may already have a number assigned. The process then isn't application — it's recovery. Different path, different steps, different timeline.
What matters most — and what trips people up constantly — is understanding that this number has nothing to do with the NIE. The NIE identifies someone before immigration authorities. The Social Security Number identifies the same person within the employment and benefits system. Different institutions, different databases, different purposes. Having one provides no automatic access to the other.
What Documents Are Required for the NUSS Application?
The paperwork is shorter than most people expect. But the specific requirements depend on nationality and legal status.
Spanish nationals: DNI only.
EU, EEA, or Swiss citizens: Passport or national ID card from the home country. If an NIE has already been assigned, it may be requested — though this varies depending on the application method and local office.
Non-EU citizens: Passport plus documentation of legal status — either TIE or a valid residence/work visa. A passport alone, without proof of authorization to work, leads to rejection.
Model TA.1: The official application form, downloadable from the Social Security website (seg-social.gob.es). This form is required for paper submissions and in-person appointments, where it must be signed. Fully digital applications through Import@ss with electronic identification skip this form entirely — the system generates the request automatically.
Contact information: A working mobile number and email address. These aren't optional fields. The system uses them for verification and communication.
That's the complete list. No utility bills. No proof of address. No employment contract. No bank statements.
How to Get a Spanish Social Security Number: The Four Methods
Spain offers four routes to obtain this number. The experience varies so dramatically between them that they barely feel like the same process.
Digital application with electronic identification
For anyone with Cl@ve, a Digital Certificate, or activated DNIe, the number generates immediately through the Import@ss portal. No form to fill. No documents to upload. No human processing delay. The system verifies identity electronically and assigns the number on the spot.
This is the method the administration prefers — and the only one that delivers genuinely instant results.
Online application without digital identification
For people who just arrived and have no Spanish electronic credentials, the Import@ss portal offers a secondary route. This requires uploading the completed TA.1 form, photographs of the identity document (front and back), and a selfie holding the document for biometric verification.
The process works. But it enters a manual processing queue. Response time depends on administrative workload — typically several days, sometimes longer during peak periods. There's no way to accelerate it once submitted.
SMS request
Only functional for people already registered in the Social Security database with a previously verified phone number. Completely useless for first-time applicants. This option exists primarily for Spanish nationals who need to recover a forgotten number.
In-person appointment
The traditional route through local Social Security offices (Administraciones de la Tesorería General de la Seguridad Social). Requires booking a Cita Previa through the official appointment system or by phone.
Availability varies enormously. Some cities offer appointments within days. Others — particularly Madrid, Barcelona, and major urban centers — can show waiting times of two to four weeks during busy periods. September and January tend to be worst, as employment cycles create application surges.
The gap between methods is stark. Digital identification means minutes. Everything else means waiting — and waiting is precisely what kills job opportunities when employers need answers quickly.
What Happens If the Application Is Rejected?
Rejections happen. Understanding why prevents wasted time on rebooking.
Unsigned TA.1 form: For manual submissions, the form requires a signature. Unsigned applications are returned without processing. The fix is simple but requires resubmitting.
Mismatched identity documents: Non-EU applicants must present documentation that matches their current legal status. Submitting a passport without the corresponding TIE or visa triggers automatic rejection. The system cannot verify work authorization without it.
Incomplete biometric verification: The online selfie requirement isn't decorative. The photo must clearly show the applicant holding their identity document in a way that allows visual matching. Blurry images, obscured faces, or photos where the document isn't legible lead to rejection and restart.
Already existing number: Sometimes applications are rejected because the person already has a NUSS assigned from previous activity in Spain — work, study, or even a brief registration years earlier. This isn't a failure; it's a redirect. The process becomes recovery rather than application, typically handled through the same Import@ss portal or by calling the Social Security information line.
Common Mistakes and Their Consequences
Waiting until an employer asks. The number can be requested proactively, at any point, even before job searching begins. Waiting until a contract arrives creates exactly the time pressure that makes the process stressful. Employers rarely wait.
Assuming the company will handle it. Article 28 of the General Affiliation Regulation technically obligates employers to request the number for workers who don't have one. In practice, many companies — especially smaller ones — simply move to candidates who are already documented. The legal obligation exists; the patience often doesn't.
Expecting healthcare access to follow automatically. This misconception causes real problems. Having a Social Security Number does not grant public healthcare. That requires a separate application: "Reconocimiento del derecho a la asistencia sanitaria." Different form, different process, different timeline. People discover this gap when they actually need medical care — the worst possible moment.
Confusing recovery with new application. Anyone who previously worked or studied in Spain likely already has a number. Submitting a new application when a number already exists creates administrative confusion and delays. Checking first — through Import@ss or the information line — takes minutes and prevents complications.
Underestimating digital identification value. Cl@ve registration is free and relatively quick. The return on that small investment is instant access to not just the Social Security Number, but dozens of Spanish administrative processes. Skipping it to "save time" creates far more waiting in the long run.
The Process Is Manageable — With One Condition
Nothing about obtaining the Spanish Social Security Number is inherently complicated. The documentation requirements are minimal. The digital system, when accessible, works efficiently. Even the in-person route is straightforward once an appointment slot opens.
The single variable that determines whether this process takes five minutes or five weeks is timing.
People who obtain the number before needing it face no pressure, no scrambling, no risk to job offers. People who discover its existence under deadline pressure enter a race against appointment availability and processing queues — a race they often lose.
The number costs nothing. Lasts forever. And takes almost no effort to obtain.
But only if the request happens before urgency arrives.
Execution Resources for SPANGOLITA Members
The members-only section contains the practical execution layer for this process — designed for people who want to complete the application correctly on the first attempt, without guesswork or rejected submissions.
What's included:
TA.1 form walkthrough: Field-by-field guidance covering the sections that cause confusion — particularly for non-EU applicants where status documentation intersects with form requirements.
Document checklist by nationality and legal status: A reference that clarifies exactly which identity documents apply to each situation, including edge cases for recent arrivals, status changes, and dual nationals.
Import@ss portal guide: Screenshot walkthrough of the digital application process, including the biometric verification step that causes rejection when done incorrectly.
The free guide above explains what to do. The members section shows exactly how to do it.
Your Route in 7 Steps
