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Why Swiss tax deduction limits change every year: the 2027 figures

Lucerne updates its franc deductions annually, Zurich every two years, the Confederation annually. Why several figures are current at once, and which year counts in January 2027.

Updated on 21.09.2026 · 7 min read

Franc amounts in Swiss tax law are tied to consumer prices, and each authority runs that link on its own clock. The Canton of Lucerne resets its tariffs and its franc deductions every year, using the consumer price index on 30 June before the tax period begins. The Canton of Zurich does the same only at the start of a two-year Steuerfussperiode, and reads the index at the end of May of the preceding year. For direct federal tax, the Federal Department of Finance adjusts annually. Several figures for the same deduction can therefore be current at the same moment: a cantonal one and a federal one, each attached to a tax year. The number you remember from last year was not wrong. It belonged to a different year.

Who recalculates, and when?

LevelRhythmIndex reading used
Canton of Lucerneevery year30 June before the tax period begins
Canton of Zurichstart of a two-year Steuerfussperiodeend of May of the preceding year
Direct federal taxevery year30 June before the tax period begins

Lucerne and the Confederation read the same index on the same date and still land on different amounts, because each level brings its own starting values. Lucerne names the rhythm itself: the offset is made annually on the basis of the consumer price index. For tax year 2027 that reading is 171.2 points against 170.4 a year earlier, a rise of 0.8 index points or 0.47 %.

Zurich reads a different month, and only every second time. Its most recent offset applies from 01.01.2026; inflation since the previous one was 1.3 %, and the child deduction moved from CHF 9'300 to CHF 9'400. The offset itself does not come round again until the next Zurich reading date, even though the index keeps moving in between.

The federal tax administration's circular on cold progression covers tax year 2026. No circular for tax year 2027 has been published.

Where the movement comes from

Your salary goes up two percent and so do prices. You can buy exactly what you could buy before, but the tax table sees a higher income and reaches one step further up. That effect is cold progression, and the remedy is to move the whole table with it: the tariff bands, and the deductions that sit in the law as fixed franc amounts.

The federal mechanics are written into the law on direct federal tax. The effects of cold progression are fully offset by adjusting the tariff bands and the franc-denominated deductions evenly, and the amounts are rounded up or down to CHF 100. The finance department adjusts them annually to the consumer price index, and the reading on 30 June before the tax period begins is the one that counts.

At federal level that rounding explains the step size: an amount there moves by hundreds or it does not move.

The mechanism also runs one way only. A negative inflation path rules an adjustment out, and the next offset after a negative stretch works from the last offset again. So falling prices never pull the amounts back down.

Deductions are not the only thing that travels. Lucerne is adjusting its income tax tariffs and its franc deductions together for tax year 2027. That is the real purpose: move only the deductions and the tariff bands stay put, still reaching income that has only grown on paper.

What happened to CHF 12'000

Lucerne carries its deduction for education and further training with an original value of CHF 12'000 and an original index of 156.7 points at 31.12.2015. Measured against the current index reading, that gives:

  • Original value: CHF 12'000
  • Inflation since the original index: 9.3 %
  • Maximum for tax year 2027: CHF 13'100

For tax year 2026 the same deduction sits at CHF 13'000. Those CHF 100 are the entire movement of one year. How much further training a canton allows at all is a different question, and the cantonal ceilings compared there are in further education costs.

Which number actually moved by 0.47 %

The 0.47 % in Lucerne's announcement describes the index. What rose was the consumer price index, from 170.4 to 171.2 points. What that turns into for any one deduction only shows up in the canton's table.

Six rows from Lucerne's decision, six different outcomes, and not one of them 0.47 %:

DeductionOriginal indexTax year 2026Tax year 2027Movement
Education and further training, max.31.12.2015CHF 13'000CHF 13'1000.77 %
Child in education away from home31.12.2010CHF 13'200CHF 13'3000.76 %
Third-party childcare costs, max.31.12.2024CHF 18'200CHF 18'3000.55 %
Insurance deduction, other taxpayers31.12.2010CHF 2'600CHF 2'7003.85 %
Insurance deduction, married31.12.2010CHF 5'200CHF 5'2000 %
Second-earner deduction31.12.2010CHF 5'000CHF 5'0000 %

Two quantities decide the outcome: the original index, the point the calculation runs from, and the original value, the franc amount it runs from. Measured from its own original index, the further-training row has accumulated 9.3 % of inflation, the childcare row 1.4 %. Both of those are cumulative figures, and neither says anything about what happened in this one year.

The two insurance rows sit furthest apart, even though they are carried on the same original index and the same inflation figure. Their original values differ, CHF 2'500 and CHF 4'900, and the published amounts stand on full hundreds in both years. One row changes its hundred, the other does not.

So scaling your own deduction with a percentage from a press release puts you in the wrong place. The percentage belongs to the index; the franc amount belongs to the table.

Every figure here belongs to the tax year named beside it, and for another year the applicable value sits in the publication of the canton you live in. Whether a particular deduction is relevant for you at all depends on your circumstances, and is worth checking against the guide for the canton you live in.

The year on the form you fill in January 2027

The tax year 2027 values are not the values on the tax return that lands in January 2027. That return covers tax year 2026. At federal level the finance department put it in plain words: the adjustment applies from tax year 2026 and becomes relevant for the first time for the tax return to be completed in 2027 for tax year 2026.

In practice, anyone completing a return between January and March 2027 works with tax year 2026 values, and the freshly published 2027 figures belong on the following year's form. A franc figure lifted from a search result is worth two checks before it goes anywhere: the tax year, and the canton.

Both are stated at the source. Cantonal tariff and deduction tables carry the year in the title, and the guide to the tax return quotes the amounts for the year it covers. A summary on an advice page often carries neither, which is where the wrong number starts.

To see roughly what a deduction is worth in your own municipality, use the tax comparison. It runs the same engine as a real TaxWize declaration, on tax year 2025 figures.

Sources

Frequently asked questions

Why is my deduction different this year from last year?
Because the franc amounts in tax law are tied to the Swiss consumer price index. When prices rise, tariff bands and franc deductions are moved with them, so that a pay rise which only matches inflation does not push you into a higher tax step. How far any single amount rises is set out in the canton's own table, and it differs from row to row.
Does a figure I find online apply to my canton?
Not necessarily. Each canton sets its own franc amounts and updates them on its own rhythm. The Canton of Lucerne recalculates every year, the Canton of Zurich at the start of a two-year Steuerfussperiode. Alongside those, direct federal tax has its own amounts, and those are the same in every canton.
Which figures apply to the return I complete in January 2027?
The tax year 2026 figures. A return completed between January and March 2027 covers income earned in 2026. The tax year 2027 values that the Canton of Lucerne has just published reach the form a year later. Naming both the tax year and the filing window avoids the most common mix-up here.
Does every canton adjust every year?
No. The rhythm is set at cantonal level. The Canton of Lucerne offsets annually and uses the index reading on 30 June before the tax period begins. The Canton of Zurich offsets at the start of a two-year Steuerfussperiode and uses the index reading at the end of May of the preceding year.
Why does one deduction rise by CHF 100 and the one next to it not at all?
Because each row carries its own original index and its own original value in francs. A row anchored in 2010 carries a good fifteen years of inflation, one anchored in 2024 almost none, and the published amounts stand on full hundreds. Across Lucerne's decision for tax year 2027, six deductions move by between 0 and 3.85 percent.

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