The OASI (German: AHV; French/Italian. AVS) number is a number assigned to all persons living or working in Switzerland: it is the social insurance number (this webpage of the Federal Social Insurance Office is available in German, French and Italian), which is also used for other administrative purposes.
The OASI number begins with the number 756, followed by random numbers. It is anonymous and does not reveal any personal information.
You are assigned an OASI number regardless of whether you are a Swiss citizen or a foreign national. Cross-border workers are also given an OASI number. You can find your OASI number on your Swiss health insurance card.
If you are an employee, you can also ask your employer for your OASI number. If you are self-employed, you can also ask your social insurance office (professional fund association or your cantonal OASI office).
You can contact your educational institution directly in order to find out your OASI number. The compensation office of the canton you study in will also provide an OASI certificate on request, using this form.
Every child living in Switzerland is given an OASI number.
You can find your children’s OASI numbers on their health insurance cards or by contacting their health insurance provider.
To find out more about the OASI number have a look at the webpage of the Federal Social Insurance Office (available in German, French and Italian) or go to the page Requesting an OASI card.
You can also find a list of frequently asked questions about the OASI number on the FAQ page of the Central Compensation Office (CCO).