What does the Social Security number mean?

Verified 14 September 2026 - Public Service / (Prime Minister)

Entry in the national register of identification of natural persons (RNIPP) gives rise to the allocation of a directory registration number (NIR).

This NIR is also called Social Security number.

This number is composed of:

  • From 13 digits
  • And of a control key from 2 digits.
Infographie - Social Security Number
Illustration X - Social Security Number - plus de détails dans le texte suivant l’infographie
Illustration X
Crédits : DILA / Service-Public.fr

Ouvrir l’image dans une nouvelle fenêtre

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

Download
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

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

Next 3 digits

Serial number to distinguish persons born in the same place at the same time period

Last 2 digits

Control key

Who can help me?

Find who can answer your questions in your region