Step 1 — Get your Vorsorgeausweis (pension certificate)
Your pension fund sends you a Vorsorgeausweis (certificat de prévoyance, in French) every January, usually as a PDF in your employee portal. If you can't find it, ask HR or log into your fund's portal directly.
The two numbers you need from it:
- Maximal möglicher Einkauf (max possible buy-in) — the gap between target capital at retirement and current accumulated capital. This is your absolute upper limit.
- Deckungsgrad (funding ratio) — the health of the pension fund. If it's below 100%, your buy-in goes into a partially under-funded scheme. Most funds are 105-115% as of 2026.
Some funds also publish your projected retirement annuity (Rente vs Kapital) on the same document — useful context, not strictly needed for the buy-in.
Step 2 — Check the Art. 79b three-year rule
BVG Art. 79b paragraph 3:
"Vom Einkauf erbrachte Leistungen dürfen innerhalb der nächsten drei Jahre nicht in Kapitalform aus der Vorsorge zurückgezogen werden."
Plain English: any buy-in you make now is locked in for at least three years. If you withdraw any pension capital as a lump-sum during that window — for retirement, for buying a house (WEF), for self-employment — the tax authority recaptures the deduction you took.
So before paying:
- Are you within 3 years of retirement, AND planning a lump-sum withdrawal? STOP. Take pension as Rente, or postpone the buy-in.
- Planning to buy a home with WEF in the next 3 years?STOP. Pay off the WEF first, then buy-in.
- Self-employed transition coming up? STOP. When you leave to start your own business, you'd typically take Pillar 2 as lump-sum — that triggers recapture.
Step 3 — Decide the amount
You can pay anywhere from CHF 1 000 up to your full Vorsorgeausweis-quoted capacity. The tax-optimal amount depends on:
- Your marginal tax rate. Above 30% marginal, every CHF you pay in saves at least 30 centimes in tax. Below 25%, the opportunity cost (money locked up, taxed lightly on the way out) starts to matter.
- Your annual cashflow. A buy-in is paid in cash, not from your pension fund. You need actually-spare francs in your bank account this year.
- Multi-year planning. Spreading CHF 100 000 over 3-5 years usually saves more total tax than paying it all at once — because each year you stay in your top marginal-rate band.
Optiqo's calculator shows the saving for a single-year buy-in. The paid plan adds the multi-year DP optimiser.
Step 4 — Pay the contribution before December 31
The deduction counts for whichever tax year the money actually arrives at your pension fund's account, not the year you initiated the transfer. So:
- Don't wait until December 30. Bank transfers can take 1-3 business days; if your payment lands on January 2, you've missed the year entirely.
- Mid-November is the sweet spot. Cleared in time, you've had 11 months to think about it, and you can still scale up/down based on your year-end income visibility.
- Use the IBAN your pension fund gives you — usually on the Vorsorgeausweis or via the employee portal. Add "Einkauf 20XX [your AHV-NAVS13]" in the payment reference.
Step 5 — Get the receipt and claim on your tax return
A few weeks after payment, your pension fund sends a Bestätigung über den Einkauf (buy-in confirmation letter). Keep this — it's the proof you'll attach to your tax return.
On your annual tax return:
- Federal direct tax (Bundessteuer): enter the amount under "Einkaufsbeiträge an die 2. Säule" (or the French/Italian equivalent). Typically section "Abzüge — Einkäufe und Beiträge an die berufliche Vorsorge".
- Cantonal tax: same amount in the cantonal section. Each canton uses its own field number; see the e-Tax software's search.
- Attach the receipt. Most cantons want it as a PDF upload alongside the return. Without it, the assessment will likely ask you to send it later.
Your assessment is recomputed with the deduction; the saving shows up either as a refund of withheld tax (employees with Quellensteuer) or as a reduced tax bill (Swiss residents on ordinary assessment).
Common mistakes to avoid
- Paying into the wrong account. "Freizügigkeitskonto" is NOT the same as your active pension fund. Buy-ins must go into the active fund.
- Mixing in a 1e plan. If you have a "Kadervorsorge" or 1e plan for income above CHF 132 300, those use separate rules. Confirm with your pension fund's HR which path your contribution goes into.
- Forgetting WEF. If you previously withdrew capital for a home purchase ("Wohneigentumsförderung"), the repayment of that WEF takes priority over any new buy-in. You can't deduct a buy-in while you still have an outstanding WEF.
- Buy-in in the year of a lump-sum withdrawal. The three-year rule starts on the day of the buy-in, not the year boundary. A buy-in in January 2026 and a lump-sum withdrawal in January 2029 is still within the window.
Quick-fire FAQ
- Can I buy in if I'm employed but my fund only covers the mandatory minimum?
- Usually yes — your fund's Vorsorgeausweis will show a non-zero "max possible buy-in" because the target benefit is computed for your full salary even on a minimum-coverage plan.
- Can I split the buy-in between my Pillar 2 and Pillar 3a in the same year?
- Yes. The two pillars are independent. Buy-in deductions reduce Pillar 2; 3a contributions reduce Pillar 3a. Both are deductible.
- What's the tax saving roughly worth?
- At a 30% marginal rate, CHF 50 000 buy-in saves CHF 15 000 in tax this year. At 40% marginal (high income, dense canton), the same buy-in saves CHF 20 000. Optiqo's calculator gives you the precise number for your profile.
- My pension fund is "under-funded" (Deckungsgrad < 100%). Should I still buy in?
- Generally caution. An under-funded fund may need to claw back capital from members ("Sanierungsmaßnahmen") — your buy-in is not protected from that. If the fund is at 95-99%, it's usually fine; below 90% wait for recovery.