How PaperTax works: documents, tax guide and AI chat

PaperTax helps you prepare your Swiss tax return using the documents you already have. It reads those documents and creates instructions for your canton's official tax app. You can ask the AI questions about the instructions and your situation. You check the information, enter it in the cantonal app and submit the return yourself.

1. Choose your canton and describe your situation

Start a return and select the tax year, canton and official language used by your cantonal app. Add your civil status, children and the types of income or assets that apply to you. PaperTax uses these details to suggest documents and prepare guidance for your situation.

You can also explain changes during the year. For example, “I started this job in November” helps explain a salary certificate that covers only part of the year. “I moved from Vaud to Zurich in July” gives the AI context that may not be clear from the documents alone.

2. Upload the documents you have

Add salary certificates, bank statements, Pillar 3a certificates, insurance statements and other relevant tax documents. A Swiss salary certificate is called a LohnausweisLohnausweisSalary certificateFRcertificat de salaireITcertificato di salarioYour employer’s annual statement of your salary, benefits and deductions. You normally receive one from each employer and use it to enter employment income in the return.Where you see itSent by your employer in January or February.Open in the glossary → in German or a certificat de salaire in French. You can upload documents in any order. You do not need to choose a category or label the fields yourself.

You can begin before every document has arrived. Add what you have now and upload missing documents later. Include the correct tax year and, where relevant, documents from every employer, bank or insurer you used during that year.

3. PaperTax reads the documents

PaperTax identifies the document types and reads the information relevant to your return, such as salary, dividends, tax withheld and pension contributions. You can open a document to compare it with the information PaperTax has read.

Reading can fail if a scan is unclear or a file cannot be processed. The app shows which document needs attention so you can try again or replace it. Check the result even when reading succeeds: the AI can misunderstand a document or a number.

4. Build the guide and read the free preview

Choose “Build my guide” when you are ready. PaperTax creates a card for each document. A card contains the field names, values and instructions you need in the cantonal app. It can also explain deduction limits or calculations that the cantonal app performs.

The explanation uses your language, while field names keep the canton’s official wording. This helps you find the matching field on screen. Open the source document whenever you want to check an amount.

You can read the first card for free. One free guide build is available per account. If you decide to continue, a one-time payment opens the full guide, further document processing and AI chat for that return. The pricing page explains the price and refund terms.

5. Ask questions and correct information in chat

The chat uses your uploaded documents and the information you gave about your canton, tax year and situation. Ask it to explain an amount, clarify an instruction or review a possible mistake. You can select an entry in the guide to start a message about it.

For example, if a Pillar 3a certificate does not include a later payment, explain that in chat and upload the final certificate when you receive it. The AI can update the guide using the new information. Check the changed entries before using them. An additional review of the guide can find inconsistencies, but it does not guarantee that every error is found.

6. Enter the information and submit in your cantonal app

Keep PaperTax open beside the official tax app, such as ZHprivateTax in Zurich or VaudTax in Vaud. Follow the instructions, compare values with your documents and mark each entry as entered when you have copied it. Marking an entry in PaperTax does not send it to the cantonal app.

When you have finished, review the completed return in the cantonal app and submit it there. PaperTax does not submit anything on your behalf. You can pause and return to the guide while working through the instructions.

When you need professional help

PaperTax provides software guidance, not professional tax advice. It does not replace the cantonal app or create a completed tax-return PDF. The broker converter produces a separate securities tax statement that you can import into a compatible app.

For a complicated or disputed tax situation, ask a qualified Swiss tax advisor. Do not rely on the AI to identify every situation that needs professional advice.

How your documents are handled

Your files and guide are stored in Switzerland. PaperTax deletes its stored data within 24 hours after you mark a return as done, or after two years of inactivity. Anthropic processes document information in the United States without using it for model training. Other providers also help run the service, and their retention rules differ. The trust page explains the providers, processing locations and deletion rules.

Where to go next

• Hold an Interactive Brokers account? Start with IBKR and foreign brokers on your Swiss tax return.
• Want to know what you can deduct? See the pillar 3a guide and Zurich tax deductions and tips.
• Taxed at source and unsure whether to file at all? Read Quellensteuer: should you file a return?

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 — ZHprivateTax — zh.ch
2. 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. 124 — SteuererklärungSteuererklärungTax returnFRdéclaration d'impôtITdichiarazione d'impostaThe return itself: the whole set of forms you complete and submit for one tax year. What the canton sends you, and what its software fills in.Where you see itThe title on the letter the canton sends, and the name of the cantonal app.Open in the glossary → (the tax return): the authority invites you to file, anyone who receives neither a personal notice nor a form must file anyway, and the return must be completed truthfully and in full — fedlex.admin.ch