What is a NUSS?

What it is

The Import@ss page for requesting the number (opens in a new tab) says: "The Número de la Seguridad Social (NUSS) is the number with which Social Security identifies you. It is also known as the Número de Afiliación (NAF)." The Social Security magazine (opens in a new tab) says the same thing in its own words: the NUSS identifies the citizen in their dealings with Social Security. A related headline on that magazine site uses the longer name Número Único de Seguridad Social (NUSS). Whether NUSS, NSS and NAF are one number is Are NUSS, NSS and NAF the same number?.

The Import@ss page says any citizen who has not been assigned a number can ask for one, and that you can ask at any time. It also says you may already have one if you have worked at some point or if you were covered by the Seguro Escolar. If you do not know the number, the page says you can check it in your personal area. The magazine adds that students under 28 in official studies, from the third year of compulsory secondary education to the end of the third university cycle, have their own number as part of the obligation to set up the Seguro Escolar.

Both pages say what the number is used for. Import@ss says you will need the NUSS to register for the first time in Social Security when you start work, and to access pensions, subsidies and benefits. It also says your autonomous community's health system will use it to register your health card and to have the right to receive health benefits. The magazine says you will need it to register as a worker or as an employer, to be paid benefits, or to receive a pension such as retirement, and that the regional health system uses it to register the health card.

The request and the autónomo alta are different services on Import@ss. The number is "Solicitar el Número de la Seguridad Social". The alta is "Alta en trabajo autónomo", described on the practical guide (opens in a new tab) as something that needs your NUSS or NAF before you can complete it. The magazine says that if you are going to be hired by a company and you have no number, the company makes the request. For other cases, it says you use the Import@ss service "Solicitar el Número de la Seguridad Social".

Import@ss also says that without a NUSS you cannot identify yourself by SMS. If you do not have Cl@ve or an electronic certificate, the page says you can do the procedure by presenting both sides of your DNI or NIE and a selfie with the front of the document. If the number is for a child, the page says the mother, the father or the legal guardian presents the request, and that they must provide the completed modelo TA.1 with the child's details. What that form is, and what it is not, is What is modelo TA.1?.

The magazine says you can also find a number you already have on an old payslip or employment contract, or on your informe de vida laboral if you work or have worked. It says that after you identify yourself in Import@ss you can see the NUSS in your personal area, or in the part called "Acreditación del Número de la Seguridad Social", from which you can download a PDF.

What is different in Euskadi

The number is assigned by Social Security, through Import@ss, for the whole system. The pages above do not give Álava, Bizkaia and Gipuzkoa different numbers or different request services. Your Hacienda Foral is a different body and does not issue the NUSS. The health-card sentence on both pages is about the health system of your autonomous community, which in the Basque Country is a regional service, but the number it uses is still the Social Security number those pages describe.

Where to read the steps

If you have never had a number, or you cannot find it, the procedure is Get your Social Security number. If you already have one and the next task is the self-employed alta, that procedure is Register with Social Security. Import@ss itself is on Apps.