The American's Swiss tax return: the four things that are different (2025)

Key takeaways

• Most of your Swiss return is the ordinary one. Salary, deductions, thresholds, the securities schedule: all the same as for anyone else.
• Four things behave differently because you are American: capital gains, pillar 3a, wealth tax, and which broker you can use.
• A Swiss-exempt capital gain is still taxed by the US, and there is no Swiss tax paid on it to credit against that.
• Keep pillar 3a in cash. Swiss funds inside it are PFICsPFICPassive foreign investment companyHow US tax law classes most non-US funds, which means nearly every Swiss or Irish-domiciled fund and ETF, UCITS included. The label matters only on the US return: it changes nothing you enter in Switzerland.Where you see itNowhere on a Swiss form. It surfaces when a US preparer asks what your fund holdings are.Open in the glossary → to the US, each needing its own Form 8621Form 8621Information Return by a Shareholder of a Passive Foreign Investment Company or Qualified Electing FundThe US return filed for a PFIC holding. One form per fund per year, for as long as you hold it, so a portfolio of several non-US funds becomes several forms annually.Where you see itFiled with your Form 1040. It has no Swiss counterpart.Open in the glossary → every year you hold it.
• Swiss wealth tax buys you nothing on the US return: the foreign tax credit relieves income tax, not a tax on net assets.

Start with the ordinary return

None of this is different for you, so it lives in the guides that already cover it:

Different 1: the capital gain that is free here and taxed there

Every Swiss personal-finance source says the same thing, and for Swiss taxpayers it is true: private capital gains are not taxed in Switzerland.

For you, half of that sentence is false. Switzerland does not tax the gain; the United States does, because it taxes its citizens on worldwide income wherever they live. And the foreign tax credit only returns tax you actually paid abroad, so on this sale, where Switzerland took nothing, the full US tax lands with nothing to set against it.

What the US does

• Taxes the CHF 10,000 gain at US capital gains rates
• Gives you a foreign tax credit only for foreign tax actually paid
• Result: you owe the full US tax, unoffset

What Switzerland does

• Taxes the gain at nothing: private capital gains are exempt
• Collects no tax on the sale, so there is none to credit
• Result: nothing to declare as income; only the year-end value counts as wealth

Nothing here is avoidable by declaring differently. It is a structural mismatch between a country that does not tax capital gains and a country that taxes its citizens abroad. The point of knowing it is to plan sales and set money aside.

Different 2: pillar 3a, decided in November

Contributions to pillar 3a can reduce your Swiss taxable income within the applicable annual limit. The payment must reach the account by 31 December to count for that year. If you are a US person, you also need to consider two US tax questions. One remains unsettled.

Settled: the contribution is not deductible on your US return. The US does not give pillar 3a the protected status it gives its own workplace retirement plans.

Unsettled: whether pillar 3a falls inside the pension article of the US–Swiss treaty. The treaty's pension provisions are generally read as covering pillars 1 and 2, and 3a is widely treated as outside them, which points toward the growth inside the account being currently taxable to you. Advisers disagree and the IRS has not ruled clearly, so ask your US preparer specifically and get the answer in writing.

What follows from both: a 3a account invested in Swiss funds holds what the US calls PFICs: passive foreign investment companies, the label US law puts on almost any fund that is not American. Each is taxed harshly and needs its own Form 8621 every year you hold it. That is why the common advice is to keep 3a in cash: you still get the Swiss deduction, without that problem.

Different 3: wealth tax, with no US relief

Switzerland taxes net wealth; the United States does not. So there is no double taxation to relieve, and no relief.

The catch is on the credit side. The foreign tax credit relieves foreign income tax, and Swiss wealth tax (VermögenssteuerVermögenssteuerWealth taxFRimpôt sur la fortuneITimposta sulla sostanzaAn annual cantonal tax on your net worth at 31 December. Switzerland taxes wealth even though private capital gains are generally tax-free.Where you see itCalculated from the totals in your securities schedule.Open in the glossary →) is levied on net assets instead, so it generally does not qualify. It is a real Swiss cost that buys you nothing on the US return, and it weighs more for you than for your Swiss colleagues when comparing cantons.

Different 4: which broker you can actually use

Swiss banks do not uniformly turn US clients away, and those that restrict usually restrict the investment side rather than the account itself, rather than carry the reporting FATCAFATCAForeign Account Tax Compliance ActThe US law that makes foreign banks identify their US clients and report those accounts. It is why a Swiss bank asks whether you are a US person, and why some of them would rather not take you on.Where you see itThe US-person question on a Swiss account-opening form, and the reason a broker asks for a W-9.Open in the glossary → puts on them: the US law requiring foreign banks to identify American customers and report their accounts. In practice Americans here cluster at Interactive Brokers, PostFinance and Swissquote for the brokerage account, whatever bank holds the salary.

Two US-specific checks while you are in there:

• Your broker needs a W-9W-9Request for Taxpayer Identification Number and CertificationThe form a US person gives a bank or broker to certify that they ARE a US person, and to hand over their taxpayer number. This is the one you sign.Where you see itYour broker's tax-residency section, at account opening or whenever they re-ask.Open in the glossary →, not a W-8BENW-8BENCertificate of Foreign Status of Beneficial OwnerThe form a NON-US person gives a broker to certify they are not American and to claim a treaty rate. If you are a US citizen or green-card holder, this is the wrong form for you.Where you see itThe same tax-residency section of a broker's onboarding, offered alongside the W-9.Open in the glossary →. The W-9 tells a bank you are American and gives them your tax number; the W-8BEN says the opposite, so if one is on file it should be replaced. The DA-1DA-1Foreign withholding tax claim formFRformulaire DA-1 (imputation d'impôts étrangers prélevés à la source)ITmodulo DA-1 (computo di imposte alla fonte)The form that claims back the foreign tax already withheld on your foreign dividends and interest. It is filed with the securities schedule, and only once your total non-recoverable foreign tax passes CHF 100.Where you see itA separate sheet attached to the Wertschriftenverzeichnis in the tax software.Open in the glossary → still matters for genuinely foreign holdings: a German or UK stock taxed at source is reclaimed the same way as for anyone else.

One folder, two returns

Document	Swiss return	Also needed for the US return
Salary certificate (Lohnausweis)	Net salary, field 11	Wage income, and the Swiss tax paid that supports your credit
Bank year-end statements	Balance as wealth, interest as income	The FBAR, and Form 8938 once your foreign assets are large enough. Each US form wants the highest balance of the year, not the December one
Broker statement (ideally an eSteuerauszug)	Securities schedule	Every sale, with what you originally paid for it, for the US capital-gains pages
Pillar 3a certificate (Bescheinigung)	The deduction	Reportable; the contribution is not US-deductible
Pension fund statement (Pensionskasse)	Buy-ins are deductible	Reporting, and the treaty position on your pillar 2
Vested benefits statement (Freizügigkeitskonto)	Not taxable wealth while tied	Reportable, though which Swiss pension accounts the FBAR reaches divides preparers

Which order to file

1. 1Swiss return due 31 March 2026Extendable on request in Zurich, and routinely granted
2. 2US return due 15 AprilAutomatic extension to 15 June if you live abroad, and to 15 October on request
3. 3FBARFBARReport of Foreign Bank and Financial AccountsAn annual report of your non-US accounts, filed if all of them added together passed 10,000 US dollars at any point in the year. It is filed with FinCEN, not with your tax return, and it reports the HIGHEST balance each account reached, not the year-end figure.Where you see itFinCEN Form 114, filed online through the BSA E-Filing system. Nothing in the Swiss return asks for it.Open in the glossary → due 15 AprilAutomatically extended to 15 October, with no form to file for it
4. 4Swiss assessment (VeranlagungsverfügungVeranlagungsverfügungAssessment decisionFRdécision de taxationITdecisione di tassazioneThe canton's binding decision on what you owe, which may differ from what you filed. Receiving it starts your 30-day objection window.Where you see itArrives by post, often a year or more after you file.Open in the glossary →) arrivesThe document that proves what Swiss tax you actually owed

Your foreign tax credit is easier to support once the Swiss assessment exists. If it will not arrive before your US deadline, extend the US return rather than estimating and amending later. An extension buys time to file, not time to pay: interest runs from 15 April on anything you owe, so pay an estimate by then if you expect a balance.

Common questions

Does my pillar 3a contribution reduce my US tax as well?

No. It reduces your Swiss taxable income and is not deductible on your US return. Whether the growth inside the account is taxable to you as it happens is genuinely disputed among practitioners. Ask your US preparer directly and get the answer in writing.

Which Swiss taxes count toward my US foreign tax credit?

Federal, cantonal and communal income tax generally do. Wealth tax generally does not, because it is levied on net assets rather than income.

What this guide does not do

PaperTax helps you prepare the Swiss return. We do not prepare, file, sign, or advise on US returns, and nothing here is US tax advice. The US points above are flagged so you know which questions to take to a US preparer, an Enrolled AgentEnrolled AgentUS tax practitioner licensed to represent taxpayers before the IRSA US federal tax qualification administered by the IRS. For US tax questions, look for someone with relevant US qualifications and experience, such as an Enrolled Agent or CPA. A Swiss Treuhänder title alone does not establish US tax expertise.Where you see itIn a tax adviser’s qualifications, when looking for help with US filing obligations.Open in the glossary → or a CPA who works on Swiss-American returns, not so you can answer them yourself. An Enrolled Agent is licensed by the US federal tax authority to act for taxpayers; a Swiss TreuhänderTreuhänderFiduciary / tax preparerFRfiduciaireITfiduciarioSomeone who prepares returns for a fee. The title is not legally protected in Switzerland, and you remain liable for the return regardless of who filled it in.Where you see itOn page 1 of the Zurich return, in the representative block, where the field is labelled Treuhänder-ID.Open in the glossary →, however good, is not.

What has and has not been checked on this page. The Swiss figures are verified against the cantonal and federal sources named below, the same as every other guide here. The US points are verified against the IRS and FinCEN pages named below, but no US-licensed practitioner has reviewed them. Treat them as the list of questions to put to one, which is what they are.

Sources

The sources below support the tax figures and rules discussed in this guide. Follow the links to check the original guidance and its scope.

1. Canton Zurich — tax return for natural persons, filing deadline and forms — zh.ch
2. Canton Zurich — form 340, securities schedule (WertschriftenverzeichnisWertschriftenverzeichnisSecurities scheduleFRétat des titresITelenco dei titoliThe list of everything you own in securities and bank accounts, with year-end values and the income each produced. It is also where you reclaim the 35% anticipatory tax.Where you see itA main section of the tax return itself, in ZHprivateTax.Open in the glossary →) 2025 — zh.ch
3. ESTVESTVThe Federal Tax AdministrationFRAFCEidgenössische Steuerverwaltung: the federal tax authority. It publishes the forms, leaflets and price lists the cantons and your tax software work from, but it is not the office that assesses you: that is your canton.Where you see itNamed as the publisher on federal forms, leaflets and the Kursliste.Open in the glossary → — form DA-1, tax period 2025 — estv.admin.ch
4. DBGDBGThe federal income tax actFRLIFDBundesgesetz über die direkte Bundessteuer: the act that governs federal income tax for the whole country. Almost every federal rule a guide cites comes from here, which is why the abbreviation appears so often beside an article number.Where you see itIn citations, as DBG Art. 33 or similar. French and Italian sources call the same act LIFD.Open in the glossary → Art. 132 — objection (EinspracheEinspracheObjectionFRréclamationITreclamoA formal challenge to an assessment decision, due within 30 days of notification. Miss it and the assessment becomes final in almost all cases.Where you see itThe deadline is printed on the assessment decision itself.Open in the glossary →) period — fedlex.admin.ch
5. IRS — Form 1116Form 1116Foreign tax creditHow US tax already paid to another country is credited against your US bill, so the same income is not taxed twice. For a US person in Switzerland it is normally what reduces the US tax on Swiss salary to nothing.Where you see itFiled with your Form 1040. The Swiss figures it needs come off your assessment.Open in the glossary →, foreign tax credit — irs.gov
6. IRS — Form 8938Form 8938Statement of Specified Foreign Financial AssetsA second report of foreign assets, filed WITH your US tax return rather than separately. Living abroad, the thresholds are far higher than the FBAR's: over 200,000 US dollars at year end or 300,000 at any point, doubled if you file jointly.Where you see itAttached to your Form 1040. It does not replace the FBAR, and many people file both.Open in the glossary →, statement of specified foreign financial assets — irs.gov
7. IRS — Form 8621, information return by a shareholder of a PFIC — irs.gov
8. IRS — Form W-9, request for taxpayer identification number and certification — irs.gov
9. FinCEN — Report of Foreign Bank and Financial Accounts (FBAR), Form 114 — fincen.gov
10. IRS — Publication 54, tax guide for US citizens and resident aliens abroad — irs.gov
11. Convention between Switzerland and the United States for the avoidance of double taxation, 1996, as amended by the 2009 protocol — fedlex.admin.ch