The three pillars, briefly
Switzerland's pension system has three pillars by design:
- Pillar 1 (AHV/IV) — state pension. Pay-as-you-go, mandatory, ~CHF 2 500/month max at 65.
- Pillar 2 (BVG / LPP) — employer pension fund. Mandatory for salaried employees above CHF 22 680/year. Funded jointly by you + employer.
- Pillar 3a — your private, voluntary, tax-favoured retirement account. The smallest of the three but the most flexible.
Pillars 1 and 2 are largely out of your control. Pillar 3a is the lever you actually pull.
What makes 3a special
Money you put into a 3a account is deducted from your taxable income for the year. At a marginal tax rate of (say) 30 %, every CHF 1 000 you contribute saves you CHF 300 in tax. The money is locked until retirement (or one of a few specific exceptions) but when you take it out, it's taxed at a separate, much lower lump-sum scale.
So the deal:
- Now: deduct contribution from taxable income → instant tax saving at your marginal rate.
- Inside the account: investment growth is untaxed (no income tax on dividends, no wealth tax on the balance).
- At withdrawal: lump-sum tax at a separate cantonal scale, roughly 4–8 % of the balance.
The new retroactive buy-in (from 2026)
Starting tax year 2026, you can retroactively fill 3a gaps from 2025 onward, up to 10 years back, after paying the current year in full. Fully tax-deductible. In 2026 that means exactly one reachable year — 2025 — because the rule has no reach behind it; the window only fills out over the coming decade.
Three limits decide what it is actually worth. The buy-in is capped at the “small contribution” of the year you pay in (CHF 7 258 in 2026), and that is the total for the year even if you cover several gap years at once. You must pay the full ordinary contribution first, so the real commitment in 2026 is CHF 14 516, not CHF 7 258. And a given year’s gap gets one buy-in and no second visit — cover a year only in part and the remainder is forfeited, so cover whole years first.
You can only fill years in which you had AHV-subject earned income in Switzerland, and you need it again in the year you pay. That makes this less useful than it first looks for someone who moved here recently: if you had no Swiss earnings in 2025, there is nothing to buy back, however large the gap appears. It is worth most to people who were already working here and underpaid — a low-income year, a career break, a year the standing order was never set up. Your 3a provider has to approve the buy-in and issue a separate certificate naming the gap years it closes; that certificate is what the tax office checks.
How many 3a accounts to open?
You can have up to five 3a accounts. The reason is purely tax-strategic: when you withdraw, lump-sum tax is progressive — bigger withdrawal = higher rate. Splitting your balance across 5 accounts and withdrawing one per year in 5 staggered years stays in the low brackets the whole way through. A typical CHF 350 000 single-account withdrawal at age 65 might be taxed CHF 25–35 k; the same balance split over 5 years can pay CHF 14–22 k. Real money.
Which provider?
Three categories:
- Traditional bank 3a account — pays you ~0.5 % interest. Safe, boring, easy. Right for someone who doesn't want investment risk.
- Traditional bank 3a fund — invests in a 25–45 % equity-allocation fund. Higher long-run returns but bank fees eat 0.8–1.5 %/year.
- Digital 3a (VIAC, Frankly, Finpension, etc.) — 99 % equity allocation possible, fees 0.39–0.55 %, full investment control. Right for anyone with >10 years until retirement who can tolerate volatility.
See our side-by-side 3a provider comparison.
Three traps to avoid
- Forgetting to actually pay it in. Many people sign up for a 3a account, deposit the first year, and forget. Set a yearly standing order for January.
- Locking your money up if you're under 30. 3a is taxed on withdrawal; if your marginal rate today is < ~25 %, the future lump-sum tax + opportunity cost might outweigh the saving. Run our calculator with your numbers.
- Underestimating fees. A 1.5 % bank-fund fee on a CHF 350 000 balance over 30 years costs you ~CHF 130 000. Switch to a digital 3a if you have the appetite.