Documents and deadlines: preparing your Geneva tax file

The key dates in the year and the documents to gather, section by section. A complete file from the start avoids back-and-forth and missed deadlines.

Key dates

December: if you are taxed at source, you receive the form to request a full assessment (TOU) or a correction for the year that is ending.
Early in the year: your salary certificates, statements and tax certificates arrive; this is the time to put your file together.
31 March: last day to file your tax return, and to request a full assessment (TOU) or a correction of tax at source. The latter deadline is strict.
Before 31 March, if needed: request an extension for your tax return (online until 31 October; fee of CHF 20 to 60 depending on the length).
After a TOU request: the request is registered within two to four weeks, then you have two months to return the tax return.
During the year: a marriage or a birth changes your tax-at-source scale; inform your employer within 14 days. If you are leaving Switzerland, contact me at least 15 days before you go.

Your situation: residence permit or FDFA legitimation card; marriage certificate, divorce or separation judgment if new; date of arrival or departure.
Income: salary certificate from each employer; tax-at-source statement (attestation-quittance) if you are taxed at source; salary statement from your international organisation if your salary is used to set the rate; your spouse’s income (for a salary paid abroad: the December payslip showing the annual total); pensions, unemployment or sickness benefits; foreign income.
Accounts and securities: year-end tax statements for all your accounts and portfolios, in Switzerland and abroad.
Property: the latest tax assessment notice for each property; for property abroad, proof of its rental value or market value; the purchase or sale deed if it dates from the year.
Debts: mortgage or loan statements at 31 December, with the interest paid.
Deductions: pillar 3a and pension fund buy-in certificates; your health insurer’s tax certificate; childcare invoices; supporting documents for your costs as a seconded expatriate.
Children: date of birth, custody arrangements; maintenance paid or received, with the judgment or agreement.

The exact list depends on your situation: I send you a targeted list as soon as I have the basic information.

Sort your documents by section: situation, income, accounts, property, debts, deductions, children.
Name each file clearly, for example “2026 – salary certificate – employer”.
Send readable, complete PDFs, with all pages; avoid blurry photos.
Documents in English are fine for me. If a translation is needed for the tax authority, I will tell you.
I tell you how to send me your documents securely.