What does the Social Security number mean?

Verified 19 August 2025 - Directorate of Legal and Administrative Information (Prime Minister)

Registration in the national register of natural persons (RNIPP) shall give rise to the allocation of a directory registration number (NIR).

NIR is also called Social Security number.

This number is composed of:

  • From 13 digits
  • And of a control key of 2 digits.
Infographie - Social Security Number
Illustration X - Social Security Number - plus de détails dans le texte suivant l’infographie
Illustration X
Crédits: Direction de l’information légale et administrative

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Social security number under scrutiny:

  • Control key
  • Birth Order No.
  • Insee Common Code
  • Department of birth
  • Month of birth
  • Year of birth
  • Sex

Social Security Number

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Social Security Number - plus de détails dans le texte suivant l’infographie
Crédits: Service Public (DILA)Infographie - Social Security Number

Social security number under scrutiny:

  • Control key
  • Birth Order No.
  • Insee Common Code
  • Department of birth
  • Month of birth
  • Year of birth
  • Sex
Tableau - Composition of the social security number

Figures

Meaning

1er digit

Sex:

  • 1: Male
  • 2: Female

    • Next 2 digits

    Year of birth

    Next 2 digits

    Month of birth

    Next 5 digits

    • If you are born in France : 2 digits of the code of the birth department (this code is the one existing at the time of birth), followed by the 3 digits of the official common code ofInsee: titleContent
    • If you are born abroad : the 2 digits of the department code are replaced by 99 and the common code by an INSEE code of the country of birth.
    • If you are born in Algeria, Morocco or Tunisia before independence of these countries: a specific code may be included instead of the 99 code and the INSEE code of the country concerned (examples: 91, 92, 93 or 94 for Algeria, 95 for Morocco and 96 for Tunisia).

    Next 3 digits

    Serial number for distinguishing persons born in the same place at the same time period

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