What the 13th salary actually is
The Swiss 13th-month salary is an additional payment equal to one month of base salary, contractually guaranteed in the vast majority of employment contracts. It is not a bonus and not discretionary: if your contract says 'CHF 100,000 annual salary including 13th', or 'CHF 7,692/month × 13', the 13th is part of the entitlement and is enforceable just like the rest of your salary.
Some sectors — banking, parts of hospitality, public administration in certain cantons — pay a 14th salary on top, typically in summer. A small share of senior or sales contracts (often in tech and consulting) replace the 13th with a discretionary bonus, but this should be explicitly written. If your contract is silent on the 13th, ask for clarification before signing.
When and how it's paid
Most employers pay the 13th in a single December payslip, usually mid-month so it arrives before Christmas. Some companies split it into two halves (June and December) to ease cash-flow seasonality for employees. New joiners get a pro-rata 13th based on the months worked during the calendar year, and leavers similarly are paid the pro-rata accumulated 13th in their final payslip.
If you switch jobs mid-year, your old employer pays out the pro-rata 13th and your new employer starts a fresh 13th calculation. Sometimes new contracts include a sign-on bonus partly to compensate for the lost full 13th, especially when joining in the second half of a year.
How it's taxed (yes, fully)
The 13th salary is treated as ordinary income for AHV, BVG, ALV and tax purposes — there is no special treatment. The full amount is taxed in the month it is received, which inflates the withholding tax on that month's payslip and is a common cause of 'why is my December net so low?' panic.
If you're on Quellensteuer (source tax), the monthly source-tax tariff implicitly assumes your annual salary including the 13th, so over the full year your withholding balances. If you file an ordinary tax return, the December figure is simply added to your yearly income and taxed at your marginal rate. The cumulative tax bill is the same whether your contract pays in 12 or 13 instalments — the 13th is not extra net, just shifted timing.
How to budget for it (and around it)
Newcomers from non-Swiss labour markets often unconsciously budget monthly off the full gross-divided-by-12 figure, then double-count when the 13th arrives. The fix is to use 'gross ÷ 13' as your monthly mental model and treat December's double pay as planned annual savings.
A common Swiss household pattern: live on 12 months, save or invest the 13th. On a CHF 100,000 salary, a typical December 13th nets around CHF 6,000–6,800 after deductions in a low-tax canton, more than enough to either max out pillar 3a for the year, contribute to a child's education savings, or rebuild your emergency fund. Don't let it disappear into restaurants and gifts by default.
Use the 13th for pillar 3a?
If you have not yet hit your CHF 7,258 pillar 3a maximum for 2026, the December 13th is the single best deployment of that money: every franc contributed reduces taxable income for the year just ending, and the tax deduction lands in the spring 2027 assessment. A 30% marginal rate saves roughly CHF 2,170 in cash taxes.
Mechanically, contribute by 30 December (banks need a day to settle) and request a tax certificate from your 3a provider for the tax return. If you've already maxed your 3a — or you're employed but already over the 2nd-pillar threshold from monthly direct debits — consider extra-mandatory 2nd-pillar buy-in (Einkauf), which is also fully deductible with similar mechanics.
Difference from a discretionary bonus
Swiss law and case law distinguish three categories: contractual 13th (Anspruch — full entitlement), 'irregular' bonus (gratification but considered salary by the courts after multiple years of similar payment), and truly discretionary bonus. Each category has different rules around prorated payment on leaving, sickness, and constructive integration into base.
Practically: a 13th is taxed at marginal rate and counted for AHV-, BVG- and ALV-bases. A discretionary bonus paid late in the year is taxed the same but doesn't count for AHV beyond the standard cap. For pillar 2 contributions, ask HR whether the 13th is included in the 'insured salary' base — some Swiss employers include only base salary, which subtly reduces your retirement build-up.
Worked examples in CHF
Example 1 — CHF 78,000 annual salary, single, no kids, canton Bern: monthly base CHF 6,000; December receives a 13th gross CHF 6,000. After AHV/BVG/ALV and Quellensteuer at the higher monthly rate, net 13th lands around CHF 4,150. Channel it into 3a: tax saving ~CHF 1,250, plus future-self gets a CHF 6,000 retirement asset.
Example 2 — CHF 140,000 annual salary, married with one child, canton Zurich, ordinary taxation: monthly base CHF 10,769; December net 13th around CHF 7,400. If 3a is already maxed, a CHF 5,000 BVG buy-in saves ~CHF 1,500 federal+cantonal tax and the rest can replenish the emergency fund.
See your 13th salary net amount
Estimate exactly what your December (or split) 13th salary will pay out after AHV, BVG and tax in your canton.
Open the net salary calculator →Frequently asked questions
Is the 13th salary mandatory by law?+
No, Swiss law does not impose a 13th. It's near-universal because most collective labour agreements (Gesamtarbeitsvertrag) and standard employment contracts include it. If your contract doesn't mention it, you don't get it.
Do I get a pro-rata 13th if I leave mid-year?+
Yes, in any year you work some months and your contract includes a 13th, the leaver pay-out includes the pro-rata portion. Always check the calculation on your final payslip.
Is the 13th paid during sick leave or maternity?+
It accrues during paid sick leave and paid maternity leave under most contracts. Unpaid absences typically reduce the 13th proportionally.
Should I treat the 13th as savings or spend it?+
Until you've built a 3-month emergency fund and maxed pillar 3a, the 13th is your single biggest annual savings opportunity. After both are covered, treat it more flexibly.
Why does my December payslip show such high tax?+
December includes the 13th, so monthly gross is double. Source-tax tariffs assume your contract pays in 13 instalments, so the year-end balances out. If you file ordinary tax, the assessment evens everything.
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