Tax returns and social security contributions

[allanb]

Am I right in thinking that if you complete the tax declaration (form 2042) and any other tax return forms that may need to go with it, like form 2047 if it applies, you will automatically comply with all reporting requirements for assessing your social security contributions?

[cooperlola]

Your tax declaration will result in the tax office calculating your RFR (revenue fiscale de reference).  This is the figure upon which your Health contributions, to your CPAM (caisse primaire d'assurance maladie) are based.  However, the tax office will not tell CPAM the figure; you will have to do this when you come off the E121.  The Social Charges (the amount you pay towards paying off the national debt) will indeed, be calculated directly from your tax return and you will get the bill in early 2008.

At least that is the way it happened for me.