A skipped year used to be gone for good
A move, a new baby or a busy December, and the pillar 3a transfer never goes out. Until 2024 that year was simply lost, together with its deduction.
Since 1 January 2025 the rules are different. A new article in the pillar 3a ordinance lets you pay missed contributions later, as a buy-in (Einkauf), and deduct them from your taxable income. This article explains who can use it, how much you can pay in, what it saves and where the traps are. Our pillar 3a calculator shows your own figure for your municipality.
The rules in one table
The buy-in is set out in Art. 7a and 7b of the pillar 3a ordinance (BVV 3), in German. The Federal Tax Administration (ESTV) explains how it applies for tax purposes in Circular No. 18a (PDF in German), in force since 1 January 2026.
| Rule | What it means for you |
|---|---|
| Oldest gap you can close | 2025. Years before 2025 cannot be caught up. |
| First possible buy-in | 2026, for a gap in 2025. |
| Time limit | Ten years. A 2025 gap can be closed until 2035, a 2026 gap until 2036. |
| Cap per buy-in year | One small contribution: CHF 7,258 in 2026, CHF 7,373 in 2027. |
| Regular contribution first | The full regular contribution for the buy-in year must be paid in. |
| Income | AHV-liable earned income in Switzerland in the gap year and in the buy-in year. |
| One buy-in per gap year | A gap year can be closed only once. What you leave open is lost. |
| No retirement withdrawal yet | After you have drawn a 3a retirement benefit, buy-ins are no longer possible. |
The Federal Social Insurance Office (BSV) summarises the same conditions (in German). AHV-liable income replacement, such as unemployment benefits or maternity allowance, also counts as income for pillar 3a purposes, according to Circular No. 18a.
How big is your gap?
Your gap for a year is the maximum you could have paid in that year, minus what you actually paid. With a pension fund, the maximum is the small contribution of that year. For 2025 and 2026 that is CHF 7,258 each. If you paid CHF 3,000 in 2026, your 2026 gap is CHF 4,258.
Without a pension fund, the maximum is 20 percent of your earned income, capped at CHF 36,288 in 2026 and CHF 36,864 in 2027. Here the gap can be much larger, but the buy-in is not. More on that below.
Maximum amounts at a glance
| Tax year | With pension fund | Without pension fund | Cap for a buy-in in that year |
|---|---|---|---|
| 2026 | CHF 7,258 | 20 % of earned income, max. CHF 36,288 | CHF 7,258 |
| 2027 | CHF 7,373 | 20 % of earned income, max. CHF 36,864 | CHF 7,373 |
The 2027 amounts come from the ESTV announcement of 5 October 2026 (in German) and apply from 1 January 2027.
What a buy-in saves: two examples from Basel
The saving is not the amount you pay in. It is the tax you no longer pay on the top slice of your income, at your marginal tax rate. We calculated two cases with the official ESTV tax calculator for the city of Basel, tax year 2027: single, no children, no church tax. The figures include federal, cantonal and communal tax. In both cases the person pays the regular CHF 7,373 for 2027 and buys in CHF 7,258 for a full 2026 gap, a total deduction of CHF 14,631.
| Taxable income before 3a | Tax without 3a | Saving on CHF 7,373 | Extra saving on CHF 7,258 buy-in | Total saving |
|---|---|---|---|---|
| CHF 95,000 | CHF 22,308 | CHF 2,042 | CHF 2,003 | CHF 4,045 |
| CHF 160,000 | CHF 41,781 | CHF 2,368 | CHF 2,335 | CHF 4,703 |
Nadia earns a taxable CHF 95,000 and paid nothing into her 3a in 2026 because she was paying for a training course. In 2027 she pays her regular contribution and closes the 2026 gap. The buy-in saves her about CHF 2,000 on top, almost as much as the regular contribution, because both amounts come off a similar slice of her income.
Tobias earns a taxable CHF 160,000. His marginal rate is higher, so the same buy-in saves him about CHF 2,300. For him, every franc in the buy-in reduces his tax by roughly 32 centimes; for Nadia it is roughly 28 centimes.
Your own figure can differ noticeably. Your municipality, civil status, children and church tax all change the rate. If you live in Basel and want the figures checked against your full tax return, see our page on tax advisory in Basel. For the basics of how the 3a deduction works, read how much tax pillar 3a really saves.
Several gaps: plan the order
Because the cap applies per buy-in year, two full gaps cannot be closed in one year. Say you missed both 2025 and 2026 in full. You could close the 2025 gap in 2027 and the 2026 gap in 2028, each time on top of the full regular contribution for that year. The 2028 small contribution is not yet published.
- Oldest gap first. The 2025 gap expires after 2035, the 2026 gap one year later.
- Small gaps can be combined. One buy-in may cover several gap years, as long as the total stays within the cap. A CHF 3,000 gap and a CHF 4,000 gap fit into one buy-in in 2027.
- Do not split a gap year. A gap year can be closed only once. If you close half of it now, the other half is lost.
A year with a high income, a bonus year for example, suits a buy-in best: the deduction then comes off a more expensive slice of income.
Self-employed without a pension fund: the cap bites
If you have no pension fund, you could have paid in up to 20 percent of your earned income. The buy-in, however, is capped at the small contribution for everyone. Example: in 2026 you could have paid CHF 36,288 and paid CHF 10,000. Your gap is CHF 26,288. In 2027 you can close only CHF 7,373 of it, and because each gap year allows one buy-in, the remaining CHF 18,915 is lost.
For the self-employed, the regular contribution remains the stronger lever. Pay it every year, ideally once your profit for the year is roughly known. The buy-in is a safety net for a small shortfall, not a way to catch up a whole year.
Taxed at source on a B permit
You can make a 3a buy-in on a B permit like anyone else with AHV-liable income. The deduction, however, only reaches you through an ordinary assessment. If your gross salary is CHF 120,000 or more, you are assessed ordinarily anyway. Below that, you have to request a subsequent ordinary assessment (nachträgliche ordentliche Veranlagung) in writing by 31 March of the following year. The request cannot be withdrawn and stays in force as long as you are taxed at source.
Our overview of when you have to file a tax return while taxed at source explains the deadlines by canton. Whether pillar 3a pays off for you at all on a B permit is covered in pillar 3a for B permit holders.
How to make the buy-in
- Pay your regular contribution for the current year in full.
- Request the buy-in in writing from your 3a foundation or insurer. You state the amount, the gap years and what you already paid in those years, and you confirm that you had AHV-liable income in the gap years and have not yet bought in for them.
- Make sure the money is credited by 31 December. What counts is the credit to your own 3a account, not the debit from your bank account.
- Attach the certificate from the foundation to your tax return. The buy-in is deducted in the year you pay it, like a regular contribution.
Keep your salary certificates for the gap years. The tax office can check years later whether you were entitled to contribute.
3a buy-in or pension fund buy-in?
The 3a buy-in is limited to one small contribution a year. A buy-in into your pension fund (2nd pillar) can be much larger, depending on your pension fund certificate. If you have both options, compare them. Our pension fund buy-in calculator shows what a 2nd pillar buy-in saves, and Tax Tip 11 on pension fund buy-ins explains when it pays off and which blocking periods apply.
Think about the withdrawal too
Every franc you pay in now is taxed again when you withdraw it, separately from your other income and at a reduced rate. That rate rises with the amount withdrawn in the same year. Two or three 3a accounts let you spread the withdrawals over several tax years. Federal rules set no limit on the number of accounts.
You can withdraw at the earliest five years before your AHV reference age, and up to five years after it if you keep working. If you stop working after the reference age, all remaining accounts fall due in the same year. And once you have drawn a 3a retirement benefit, no further buy-ins are possible. Our comparison of the capital withdrawal tax in eight cantons shows what spreading the withdrawals is worth. How to invest the money until then is covered in stock strategy versus savings account.
Why this matters beyond the tax return
A buy-in is a decision for the next ten years, not only for one tax return. Which gaps you close, in which order, alongside a possible pension fund buy-in and with the later withdrawals in mind: that belongs in your retirement planning. If you want an outside view of how your 3a fits your wealth and goals, our financial advisory looks at the whole picture.
Every case is different, the potential usually is not
Whether a buy-in pays off and how much it saves depends on your income in the buy-in year, your municipality, your pension situation and your plans for the withdrawal. This article sets out the rules and simplified examples; it does not replace individual advice.
What does generalise: since 2025 a missed year is no longer lost, but every gap closes after ten years and the cap is tight.
Related FIN services
- Retirement Planning
- Financial Advisory
- Pillar 3a Calculator
- Pension Fund Buy-in Calculator
- Vested Benefits Account
- Tax Return Switzerland
Status October 2026, tax year 2026; example calculation for tax year 2027. This article is for general information and does not replace individual tax or legal advice. Figures: ESTV tax calculator, calculated on 14 October 2026.