Why TaxWize
What your 2025 tax return tells you about 2026
Your 2025 return shows gaps that are still open for 2026, and for Pillar 3a that window closes on 31.12.2026. Why autumn is the right moment, and what TaxWize shows you.
Updated on 28.09.2026 · 7 min read
Your 2025 tax return looks backwards. It's also the only document where a household's whole year sits on one table: both salary certificates, both Pillar 3a certificates, the daycare invoices, the year-end bank statement. Whatever is missing from it can't be fixed for 2025 anymore. It can for 2026, and for Pillar 3a you have until 31.12.2026, because you can only deduct what was actually paid in during that year.
So a gap you spot in October while finishing the 2025 return is still open for the 2026 one. The tax analysis in TaxWize usually closes with a section on the year ahead, as long as your documents give it something to work with.
The service booklet, not the invoice
The garage invoice tells you what the last service cost. The service booklet tells you what's due next. Same workshop, but only one of them helps you next year.
Most people treat a tax return like the invoice: fill it in, file it, forget it. The form invites that, since it asks about last year and nothing else. When I built the TaxWize tax report, I wanted it to do both jobs: settle 2025, and point at whatever in 2026 can still be moved.
Why autumn, of all times?
If you extended your 2025 filing deadline, you're filling the return in right about now. That puts the look back at a moment when a full quarter of 2026 is still ahead of you. The same finding in March would just be a reminder of something you can no longer do.
Zurich's cantonal guide for 2025 puts it plainly: only contributions actually paid in 2025 may be deducted. The mechanism is the same for 2026, just with 2026 in it. Pay in during December 2026 and it counts for the 2026 return. Pay in during January 2027 and it counts for 2027.
The 2026 caps are the same as 2025's. Employees who belong to a pension fund can deduct up to CHF 7'258 for 2026. Those without a pension fund can deduct up to 20 % of their earned income, capped at CHF 36'288. For a married couple the deduction applies to each employed spouse separately, as long as each has signed their own pension contract. If one of you doesn't have a 3a account yet, a December payment needs one opened first, one more reason to look now.
These caps are the same in every canton. They come from a federal ordinance and apply to the direct taxes of the Confederation, the cantons and the municipalities alike. Living in Aarau, Lucerne or Zug doesn't change the maximum. It does change what each deducted franc is worth in the end.
What 2025 can show you about 2026
Not every oddity is a missed chance. Often it's just a certificate that never got uploaded. TaxWize runs fixed rules over the 2025 return to spot the patterns in the left column. The right column is my reading of what such a pattern can mean for 2026. It isn't something the software prints:
| What stands out in the 2025 return | How I'd read it for 2026 |
|---|---|
| Pillar 3a for only one spouse | If the second spouse is employed, a contribution of their own is still possible for 2026 |
| No Pillar 3a for a single filer | A 2026 contribution is still possible, and the 2025 gap can be bought in from 2026, under conditions |
| Children in the household, no childcare costs | If you pay for childcare, the 2026 receipts can be kept as they come in |
| Property you own | Maintenance receipts can be filed as the work happens |
| Securities in a custody account | The 31.12.2026 statement can be requested early in the new year |
Most of the money sits in the first row.
CHF 1'517.85 from a second Pillar 3a
Take a married couple in the City of Zurich. Both are employed, both have a pension fund, neither pays church tax. Their 2025 return shows a 3a contribution for one of them only. For 2026 they expect a taxable income of CHF 100'000, assumed the same for cantonal and federal tax. The second spouse opens a 3a account in November and pays in the full amount for the first time in December 2026.
| without second 3a | with second 3a | |
|---|---|---|
| Taxable income | CHF 100'000 | CHF 92'742 |
| Cantonal and municipal tax (incl. personal tax) | CHF 10'198.00 | CHF 9'023.15 |
| Direct federal tax | CHF 1'816.00 | CHF 1'473.00 |
| Total | CHF 12'014.00 | CHF 10'496.15 |
Paying in CHF 7'258 cuts their 2026 tax by CHF 1'517.85, just under 21 centimes per franc. CHF 1'174.85 of that comes off the cantonal and municipal bill, CHF 343.00 off the federal one. The figures come from the Canton of Zurich's own tax calculator for tax year 2026, which rounds the taxable income down to CHF 92'700. And the money isn't spent. It sits in the second spouse's pension account.
Those 21 centimes belong to this income in this municipality. On a lower income, or in a municipality with a lower tax multiplier, the same franc saves less, as what a tax deduction actually saves walks through. Caps, tariffs and multipliers are set per year, so for any other year it's the canton's current figures that count.
The saving shows up with the 2026 return, which you'll fill in from January 2027. The certificate from the 3a provider for the December payment goes in with it as an attachment; Zurich's guide asks for it. Put it next to the salary certificates when it arrives and you won't be hunting for it in spring.
What TaxWize does here, and what it doesn't
The calculation itself runs on a fixed rule set per canton. From your 2025 documents TaxWize works out the tax and, with equally fixed rules, patterns like the ones in the table. An AI model then writes the text of the tax analysis, and the report marks it as "AI-assisted". Your documents and the analysis stay on servers in Switzerland.
What the analysis can't do is see past the documents. If the second spouse did pay into a 3a in 2025 and only the certificate is missing, TaxWize's rules treat that first as a certificate that may be missing, not as a missed payment. Add it and the 2025 calculation changes, and there's no 2025 gap to close at all.
Your bank will show you your own 3a account faster. The comparison between two people only exists where both salary certificates and both 3a certificates sit side by side, which is the tax return. The analysis doesn't replace personal pension planning, though. Whether a payment makes sense for your household, and how large, depends on more than tax, and that's a conversation for a pension specialist.
TaxWize prepares the 2025 return for Aargau, Zurich, Lucerne, Solothurn, Bern, Zug and Schwyz, at CHF 39 per return and tax year, and the tax analysis is part of the report. To see first how much your municipality alone moves the result, try the free tax comparison.
Sources
- Canton of Zurich, Wegleitung zur Steuererklärung 2025, Beiträge an die 3. Säule a [Ziffer 14] (caps CHF 7'258 and CHF 36'288, only contributions actually paid in 2025, deduction per employed spouse with their own pension contract, certificates attached to the return): https://www.zh.ch/content/dam/zhweb/bilder-dokumente/themen/steuern-finanzen/steuern/natuerlichepersonen/2025/est-wegleitungen/305_Wegleitung_ZH_2025_HA%20bf%20DEF.pdf (retrieved 28.09.2026)
- Federal Tax Administration (ESTV), "Zinssätze / Höchstabzüge Säule 3a bei der Direkten Bundessteuer DBST", table of maximum Pillar 3a deductions (2026: CHF 7'258 with a pension fund, CHF 36'288 without; 2025 identical): https://www.estv.admin.ch/de/zinssaetze-hoechstabzuege-saeule-3a-direkte-bundessteuer (retrieved 28.09.2026)
- Federal Social Insurance Office (BSV), "Die dritte Säule", published 10.02.2026 (deduction for the direct taxes of the Confederation, cantons and municipalities under Art. 7 para. 1 BVV 3, small contribution CHF 7'258 from 2025, large contribution capped at CHF 36'288 from 2025, AHV-liable earned income as a condition, buy-ins first possible in tax year 2026 for 2025): https://www.bsv.admin.ch/bsv/de/home/sozialversicherungen/bv/grundlagen-und-gesetze/grundlagen/einkaeufe-saeule-3a.html (retrieved 28.09.2026)
- Canton of Zurich, official tax calculator, income and wealth tax plus direct federal tax, tax year 2026, City of Zurich, married tariff, no denomination, taxable income CHF 100'000 and CHF 92'742: https://www.zh.ch/de/steuern-finanzen/steuern/steuern-natuerliche-personen/steuererklaerung-natuerliche-personen/steuerrechner.html (retrieved 28.09.2026)
Frequently asked questions
- By when do I have to pay into Pillar 3a for it to count for 2026?
- Within 2026. Only contributions actually paid during the tax year are deductible; the Canton of Zurich's 2025 guide says so in so many words. A payment made in January 2027 counts for the 2027 return instead. For 2026 the maximum for employees with a pension fund is CHF 7'258.
- Can both spouses deduct Pillar 3a?
- Yes, if both are gainfully employed and each has their own Pillar 3a contract. The deduction works per person, up to CHF 7'258 each for 2026 when both belong to a pension fund. Whether that applies to you depends on both of you having earned income subject to AHV contributions.
- What if nothing went into Pillar 3a in 2025?
- From 2026, a 2025 gap can be closed with a buy-in, under conditions. One of them is that the ordinary contribution for the year of the buy-in has been paid in full, and in 2026 the buy-in itself is capped at CHF 7'258. The details are in the article on the Pillar 3a buy-in.
- Does TaxWize tell me how much to pay in?
- No. The tax analysis shows what stands out in your documents and usually draws a few ideas for next year from it. It's written by an AI model, marked as AI-assisted in the report, and it isn't personal advice. The right amount for your household depends on your circumstances.
Related guides
Keep your deductions in view
TaxWize reads your documents, surfaces deductions that may be relevant, and prepares your tax return for filing. CHF 39 per tax return per tax year.
Explore TaxWize