Tax return in the Canton of Zurich: which documents you need to gather
Updated: · General information, not tax advice
In short: with your salary certificate and last year's return the frame is standing. Everything else is receipts for individual line items — and the three that go missing most often (pillar 3a, year-end balance statements, medical costs) are exactly the ones that cost money when they are not there.
The slow part of a tax return is rarely the filling in. It is the hunting: which receipt belongs to which line item, which one is already here, which one only arrives in February. This page is the list we work through ourselves — in the order it is needed.
1. The short list: what almost everyone needs
- Salary certificate (Lohnausweis) for the tax year — from every employer, including if you changed jobs mid-year.
- Last year's tax return, if you have it. Not compulsory, but the best cross-check there is.
- Interest and year-end balance statements for your accounts, as at 31 December.
- Health insurance premium statement.
- Pillar 3a certificate, if you pay into one.
2. What gets added depending on your situation
- Voluntary purchase into the pension fund (2nd pillar): the fund's confirmation.
- Childcare: invoices from the nursery, childminder or after-school care.
- Further training: invoices and, if you have it, confirmation that your employer did not cover the cost.
- Donations to recognised organisations.
- Medical costs: deductible, franchise, dentist, glasses — only deductible above the canton's threshold, but worth collecting.
- Debt interest and account statements for loans.
- Maintenance payments you make or receive.
- Securities: portfolio statement and the bank's tax statement.
- Crypto: the exchange's annual statement or a wallet overview as at 31 December.
- Foreign accounts and property abroad: statements and receipts.
- Home ownership: mortgage interest, imputed rental value, maintenance costs.
3. The three that go missing most often
In our experience always the same three — and all three cost money when they are missing:
- The pillar 3a certificate. It arrives in January by post or in your e-banking and often gets put aside, because it looks like an advert.
- Balance statements for second and third accounts. Everyone remembers the main account; the old savings account, or the one back home, not so much.
- Medical costs. They sit spread over twelve months of insurer statements and almost never get added up.
4. What format to send them in
PDF, JPG, PNG or DOCX, at most 10 files and at most 10 MB each. Scans are welcome. Clearly legible PDFs speed up the check, because fewer line items have to be read by hand.
If something is missing: send what you have. You get a list of what is still open in the reply, before anything moves on.
5. If you pay withholding tax, your deadline is a different one
If the tax is deducted straight from your salary, you do not automatically file a return — that takes a request, and the request has a forfeiture deadline on 31 March that is not extended. That is a topic of its own: withholding tax and the subsequent ordinary assessment.
And if you only want to know how long you have: deadline and extension in the Canton of Zurich.
6. How we help
We prepare your tax return from these documents, or we check the one you have already done, line by line against your receipts, with a second independent AI check and a sealed verification log. Fixed price CHF 49. Today we work the Canton of Zurich.
The first result is free: you learn how many line items add up and how many need attention, before you pay anything.
See how it works and get started →
7. Frequently asked questions
What is the minimum I need to get started?
The salary certificate for the tax year and last year's tax return, if you have it. Those two are enough to build the frame; the rest are receipts for individual line items, and they can still be handed in later.
What if a receipt is missing?
Send what you have. We tell you in our reply what is still missing before anything moves on — a missing receipt usually just means one line item stays open, not that the whole return waits.
Do I really need last year's tax return?
It is not compulsory, but it helps a lot: it shows which deductions were accepted last year and which assets are declared. Without it the cross-check takes longer and more line items stay open.
In what format should I send the documents?
As PDF, JPG, PNG or DOCX, at most 10 files and at most 10 MB each. Scans are welcome; clearly legible PDFs speed up the check, because fewer line items have to be read by hand.
8. Notice
This page is general information about the documents used in a tax return and does not constitute tax or legal advice. Which deductions apply, and up to what amount, depends on your situation, your canton and your municipality; other cantons have their own rules. You file the return yourself.