Switzerland's 20% down problem: pillar 3a fills the gap

Pillar 2 (the occupational pension, BVG) cannot be used for the first 10% of hard equity. Pillar 3a (the tied private pension) can.

Buying a home in Switzerland starts with a number everyone quotes: 20% down. A bank finances at most 80% of a property's value, and the buyer brings the rest. That part is well known. The part that catches people is the rule inside the rule. We covered the regime in why Swiss mortgage lenders are so conservative and the affordability arithmetic in the FINMA math; this piece is about funding the deposit itself.

Of the 20%, at least half, a full 10% of the property's value, must be “hard” equity that does not come from your occupational pension (pillar 2). That is the binding constraint for most buyers, and it is where plans quietly fail. A household can have a large second-pillar balance and still be short on the deposit, because the rules will not let the second pillar fill the first 10%.

Stated plainly, because the distinction is the whole article: pillar 2 (the occupational pension, BVG) cannot be used for the first 10% of hard equity. Pillar 3a (the tied private pension) can. They are different pillars with different rules, and conflating them is the single most expensive mistake a first-time Swiss buyer makes.

The thesis follows from that: for a salaried buyer, pillar 3a is the one tax-advantaged savings vehicle that both builds the deposit and counts as the hard equity the bank requires. The rest of this piece works through what qualifies, how 3a works, how to deploy it, and what 15 years of it is actually worth.

The 20% splits into two tranches with different rules.

The first 10% (hard equity) must come from sources independent of the occupational pension:

• cash and bank savings
• securities (a portfolio in a custody account)
• pillar 3a (tied private pension)
• gifts (Schenkung) from family
• advance inheritance (Erbvorbezug)

The second 10% can be anything from the list above, and may additionally draw on pillar 2, by withdrawal or pledge.

Why is pillar 2 walled off from the first 10%? The FINMA-recognised self-regulation requires that genuine equity be at least 10% of the lending value and may no longer come exclusively from pension assets (SBA minimum-requirements guidelines, FINMA-recognised). The supervisory logic is that the occupational pension is retirement security first; allowing a purchase to be funded entirely out of it would leave both the household and the system thinner against a downturn, the lesson the regime took from the 1990s that piece one covers. Pillar 3a sits outside that wall because it is private, tied saving the holder has already set aside as discretionary capital.

Pillar 3a is tax-advantaged tied retirement saving. Contributions are deductible from taxable income at federal, cantonal, and communal level, which is the lever this whole article turns on.

The 2026 annual maximum:

• CHF 7,258if you are employed and already in an occupational pension (the “small 3a”, BVV3 art. 7(1)(a)), unchanged from 2025 (VIAC, 2026 maximum).
• 20% of net earned income, capped at CHF 36,288, if you are self-employed without a pension fund (the “large 3a”, BVV3 art. 7(1)(b)) (UBS, pillar 3a maximum 2026).

One aside that trips up founders: an owner of an AG or GmbH who draws a salary is treated as employed, so the CHF 7,258 cap applies, not the 20% one.

How the money is held matters over a long horizon. Modern investment-based 3a (VIAC, Finpension, Frankly) holds the balance in equities and bonds; traditional bank 3a pays a low account rate. Over the 10 to 20 years a deposit plan runs, the difference between an invested 3a and a bank 3a compounds into real money, which the worked example below quantifies.

Outside of standard retirement, pillar 3a can be drawn only in defined cases: leaving Switzerland for good, becoming self-employed, or buying owner-occupied property under the home-ownership promotion (WEF) rules. The last is the one that turns a retirement account into a deposit. You can model your own contribution path with the pillar 3a calculator.

There are two ways to put pillar 3a to work for a purchase, and they are not equivalent.

Withdrawal (Vorbezug). The capital is paid out and goes into the down payment. It triggers the capital-withdrawal tax (Kapitalauszahlungssteuer), levied separately from ordinary income at a reduced rate. Crucially, pillar 3a has no minimum withdrawal, unlike pillar 2, where the WEF advance must be at least CHF 20,000 (WEFV, SR 831.411; finpension). Both pillars share the other two conditions: a WEF withdrawal is permitted only every five years, and only for an owner-occupied primary residence, never an investment property. Once 3a is withdrawn, you cannot pay it back in.

Pledge (Verpfändung). The capital stays in the 3a account, invested and earning returns, and is pledged to the bank as collateral. Because nothing is paid out, no capital-withdrawal tax is triggered. The pledge supports a larger mortgage; the bank can claim the pledged funds only if you default (UBS, pillar 3a for residential property). The trade is a higher mortgage and therefore higher lifetime interest.

The capital-withdrawal tax itself is layered (federal, cantonal, communal) and taxed separately at a reduced rate, roughly 3% to 10% across cantons depending on the amount and a mildly progressive scale. Zug, the canton in our running example, is among the lowest: about 2.81% on a CHF 100,000 withdrawal, roughly CHF 2,810 (finpension, capital-withdrawal tax by canton).

The choice between the two feeds straight into the amortisation schedule from the FINMA math: a withdrawal lowers loan-to-value directly, shrinking the second-mortgage balance that must be amortised to two-thirds within 15 years; a pledge keeps loan-to-value high, leaving a larger amortisation obligation. One forward-looking caveat: once the imputed-rental reform takes effect (expected 2028, with the Federal Council signalling a 2029 start, EFD) and mortgage interest is no longer broadly deductible, the pledge route's “keep a large deductible mortgage” advantage weakens, tilting the calculus modestly toward withdrawal.

A couple in Zug plans to buy a CHF 1,200,000 property in 15 years. The requirement: 20% down, or CHF 240,000, of which the hard-equity half is CHF 120,000. Assume a marginal income-tax rate of about 22% (Zug, household income about CHF 200,000) and, for invested 3a, a 3% annual return (stated as an assumption, not a forecast). Three ways to reach the CHF 120,000.

The pattern is not subtle: the tax shield plus compounding inside pillar 3a strictly dominate cash savings for the same nominal target. The same francs, routed through 3a, both cost less after tax and grow while they wait. Once you know the deposit you need, the mortgage affordability calculator shows what that 20% translates to as a maximum purchase price.

Withdrawal-tax figures apply finpension's ~2.81% modelled rate at CHF 100,000 as a simplification; Zug's tariff is mildly progressive and the precise rate scales modestly upward for the larger amounts in (b) and (c).

• Max pillar 3a from the first year of Swiss residency. The compounding of the tax shield over 15-plus years is the largest single piece of leverage available to a salaried buyer assembling a deposit.
• For a first purchase, the route depends on two questions. A pledge preserves invested capital and the deductible mortgage; a withdrawal lowers the mortgage and the long-run interest cost. Which wins turns on whether you expect 3a returns to keep outpacing the mortgage rate, and on the post-2028 mortgage-interest deductibility question.
• The three-year reclaim window is a real option. If a pillar 2 WEF advance is repaid, the capital-withdrawal tax can be recovered. Worth knowing before, not after, the withdrawal decision.
• Pillar 3a economics change for readers who may leave Switzerland before retirement; that case is the subject of a future piece in this series.
• Investment-based 3a outperforms bank 3a over long horizons. Over a 15-year deposit plan the gap is material, and it is the difference between the numbers above and a flat account balance.