Swiss federal social security identification number required for employment, taxation, and pension contributions, issued by the Central Compensation Office (ZAS).
The AHV-Nummer (Alters- und Hinterlassenenversicherung number, or Old-Age and Survivors Insurance number) is Switzerland's federal social security identification number, equivalent to a social security number in Anglo-American systems or an identification number for national insurance purposes. Every person working in Switzerland or receiving Swiss social benefits must have an AHV-Nummer. The number is issued by the Central Compensation Office (Zentrale Ausgleichsstelle, ZAS) and is fundamental to Swiss employment, taxation, and pension systems. The AHV-Nummer remains the same throughout your life and serves as your primary identifier for all Swiss social insurance contributions.
For Swiss citizens, the AHV-Nummer is assigned automatically at birth through the civil registry. For non-Swiss residents and workers, the number must be requested from the ZAS or through your employer. The assignment is free and occurs within days of a valid request. Your employer will typically request the AHV-Nummer during the hiring process; without one, employment cannot commence legally. For self-employed persons and business owners, the AHV-Nummer is essential for registering your business with cantonal authorities and the Swiss commercial register (Handelsregister). The number is printed on all pay stubs and annual tax statements.
The AHV-Nummer is integrated into Switzerland's mandatory social insurance system (AHV/AVS, the Old-Age and Survivors Insurance system). All employed persons must contribute to AHV, with contributions split between employer and employee (approximately 8.4% of gross salary combined). Self-employed persons contribute approximately 9.8%. These contributions fund retirement pensions, survivor benefits, and disability insurance. The AHV system is "pay-as-you-go"—current workers' contributions fund current retirees' benefits. Your AHV contributions accumulate as work credits (Beitragsjahre); you must have at least 1 year of contributions to qualify for AHV pension benefits.
The AHV-Nummer also serves as the identifier for the second and third pillars of Swiss pension savings (occupational pensions and private retirement accounts). Your employer's pension plan (Pensionskasse) links to your AHV-Nummer to track vested benefits. Private retirement savings accounts (3rd Pillar, Säule 3a and 3b) are identified by your AHV-Nummer as well. Coordination of multiple employer pensions, vesting calculations, and pension payouts all depend on the AHV-Nummer as the central identifier. Errors in the AHV-Nummer (incorrect digits, spelling variations) can cause pension credits to be lost or misattributed.
For expats and foreign workers, the AHV-Nummer is a critical administrative requirement. Without it, employers cannot legally employ you. Banks may refuse to open accounts without one. Tax filings require the AHV-Nummer. Long-term residents should verify that their AHV-Nummer is correctly registered with the ZAS; errors can result in missing pension contributions or difficulty claiming benefits later. When you depart Switzerland, your AHV account remains active if you meet vesting requirements; you can later claim AHV benefits as a retiree even if no longer resident in Switzerland. Non-EU workers departing Switzerland can sometimes claim partial refunds of AHV contributions in certain circumstances.
Your employer typically requests the AHV-Nummer from the ZAS during your hiring process. If your employer doesn't request it, contact the ZAS directly or your cantonal AHV office. The request is free and processed within days. You'll receive notification with your assigned number. The AHV-Nummer is printed on pay stubs and official correspondence.
You inform each new employer of your AHV-Nummer. Your contributions continue to accumulate in your same AHV account throughout your working life, regardless of employer changes. Each employer reports your contributions to the ZAS; the ZAS coordinates and consolidates contributions. You don't need to request a new number or re-register; the same number is used with each employer.
Yes, you can claim AHV pension benefits when you reach retirement age, even if you're no longer living in Switzerland. However, you must have at least 1 year of contributions to qualify. If you worked fewer than 12 months in Switzerland, you may be able to claim a partial refund of your contributions in certain circumstances. You must apply for your pension through the ZAS or your cantonal office approximately 3 months before retirement.
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