St. Gallen tax return: E-Tax SG 2026
for the self-employed

As a self-employed person, you complete your St. Gallen tax return for the 2026 tax year entirely online in E-Tax SG, the canton's filing app. You log in with the E-Login (AGOV), enter your business profit in Ziffer 2 (item 2 of the return) and attach a statement of income and expenses, assets and liabilities, and private withdrawals and contributions.

Your AHV contributions (old-age and survivors' insurance, AHV/AVS) are already included in your business result, and pillar 3a goes in Ziffer 13. You must file by the date on page 1 of your tax return, usually 31 March. If you can't make it, request an extension before then.

This guide is for you if you live in the canton of St. Gallen and run a sole proprietorship, work freelance or are self-employed alongside a job. As of November 2026. The 2026 Wegleitung (the canton's official guidance notes) has not been published yet. Where we rely on the 2025 Wegleitung, we say so. The canton's portals and forms are in German, so the German field names are given below with a translation.

Sound familiar? In March, thousands of people search for "St. Gallen tax return", and almost every answer only explains the login. That's enough for employees.

As a self-employed person, you need more: What do you have to attach? Where does the profit go? What happens with AHV and 3a? That's exactly what we cover here, field by field, with sources from the canton.

The essentials in 30 seconds

• Where: in E-Tax SG, the canton's web application (etax.sg.ch). Since the 2025 tax period, there is no longer a downloadable software version.
• Login: the canton's E-Login, based on AGOV. Instead of a password, you confirm with the "AGOV access" app or a security key.
• Deadline: the date on page 1 of your tax return, usually 31 March.
• Extension: online with your Register-Nr. (register number) and date of birth, before the deadline expires and only if your tax bills that are due have been paid.
• Required attachment for the self-employed: balance sheet and income statement or, if you have no duty to keep full accounts, a statement of assets and liabilities, income and expenses, and private withdrawals and contributions.
• Help: E-Gov support 058 229 10 10, live chat for tax questions at steuern-sg.chat, and your Gemeindesteueramt (municipal tax office).

Do you keep your invoices and expenses in Magic Heidi? Then you already have most of the key figure for Ziffer 2. We show how to use it in the section "Prepare your business figures".

What's different about E-Tax SG (and what's new for 2026)

Web app instead of a download, login with AGOV

E-Tax SG runs in your browser, on a computer as well as on a smartphone. You don't install anything, and the app carries over last year's data automatically.

For the login, the canton uses AGOV, the federal government's login for public authorities. Registration is guided. The canton recommends doing it on a computer.

A known stumbling block: after you scan the QR code, the message "ETAX.CH – Es ist ein Fehler aufgetreten" (an error has occurred) appears. In that case, reopen E-Tax SG via the link and log in again. If that doesn't help, contact the E-Login support.

If you want to practise first, etaxdemo.sg.ch has a demo with three sample cases. You need an E-Login for it, but nothing is submitted. Explainer videos on E-Tax SG, for example on uploading receipts, eFiling and the Freigabequittung (release receipt), are on the canton's E-Tax SG page.

New for the 2026 tax return

The 2026 tax return is the second year with E-Tax SG. Since 2 July 2026, you can pre-enter data and receipts for the next period, such as medical costs.

Since 24 August 2026, E-Tax SG converts selected foreign-currency amounts into Swiss francs. In the year-on-year comparison, a new "Abweichung" (difference) column shows the change from the previous year. That's handy for the self-employed: if your profit jumps sharply, you see it straight away.

Before you start: the documents you need

Have these ready before you open E-Tax SG:

• Register-Nr. and Zugangscode (access code), at the top right of your paper tax return
• Your 2026 business figures (see the next section)
• AHV contribution decisions and bills from your compensation fund for 2026
• 3a certificate from your bank or insurer, and if applicable the certificate for a buy-in to your pension fund (2nd pillar, BVG/LPP)
• Salary certificate, if you're also employed
• Bank and securities statements as of 31 December 2026

Watch out with PDFs from banks: files with a digital signature or password protection can't be submitted. More on this in the section "Submitting".

Prepare your business figures

This is the part that sets the self-employed apart from employees. For everything general, such as expenses, vehicle or home office, see our general guide to the tax return for the self-employed. Here we only cover what St. Gallen wants to see.

Duty to keep accounts or not: what St. Gallen wants to see

In Ziffer 2.1, you declare the income from your own self-employed activity. According to the 2025 Wegleitung (as of Nov 2026), this expressly includes income from online platform activities (Online-Plattformaktivitäten). Ziffer 2.2 is for shares in general and limited partnerships (Formular 11) and in simple partnerships (einfache Gesellschaften).

What you attach depends on whether you have a duty to keep accounts (Buchführungspflicht):

• With a duty to keep accounts (from CHF 500,000 turnover): balance sheet, income statement, private accounts and depreciation table.
• Without a duty to keep accounts (most freelancers): you still have to keep records of your income, expenses and assets. The Wegleitung says: "Der Steuererklärung ist auf jeden Fall eine Aufstellung über Aktiven und Passiven, Einnahmen und Ausgaben sowie Privatentnahmen und -einlagen beizufügen." In other words: in every case, a statement of assets and liabilities, income and expenses, and private withdrawals and contributions must be attached to the tax return. Formular 15a (form 15a) of the Federal Tax Administration (ESTV/AFC) helps with this.

Our article on year-end closing for a sole proprietorship explains how to put the accounts together yourself. Keep all records relating to your self-employed activity for 10 years.

The year's income and expenses: export them from Magic Heidi

If you record your invoices and expenses in Magic Heidi throughout the year, the most tedious part is already done. For 2026, Magic Heidi shows you your revenue, your expenses by category and your profit, all excluding VAT (MWST).

You export these figures as an Excel file. They are the basis for the statement of income and expenses that St. Gallen requires.

One point deserves attention: by default, Magic Heidi counts only paid invoices in these figures. The ESTV's Formular 15a, which the Wegleitung refers to, however adds the receivables at year end to the payments received and deducts those from the start of the year.

So include the invoices still open at the end of 2026 in your statement, as revenue and as receivables under assets, or clarify with the tax office whether you may report on a cash basis (when payment is received). Invoices from 2025 that were only paid in 2026 belong to the previous year. List unpaid business bills at year end as debts.

To be honest, that doesn't finish the statement. You or your fiduciary add assets and liabilities, private shares, depreciation, and private withdrawals and contributions. Magic Heidi doesn't file a tax return and doesn't produce official year-end accounts. But it gives you clean annual figures, instead of you digging receipts out of three folders in March.

Take Lena, a fictional graphic designer with a sole proprietorship in Wil (figures for illustration). In 2026, she has CHF 78,000 in revenue and CHF 21,000 in expenses, so CHF 57,000 in profit, and she isn't subject to VAT.

In January, she exports her annual figures from her invoicing software and adds the December invoice her client hasn't paid yet. She paid her electricity and internet bills through the business, so she adds the St. Gallen private share for a one-adult household. She enters the result in Ziffer 2.1 and uploads the statement as a supporting document. That takes care of the business part in one evening.

Not that organised yet? If you record every invoice and every receipt in Magic Heidi from January 2027, your annual figures for your next St. Gallen tax return will be ready in minutes.

Private share: the St. Gallen flat rates

Did you run private household costs through the business, such as heating, electricity, gas, cleaning, communication, or radio and TV? Then, according to the 2025 Wegleitung (as of Nov 2026), you add back a flat-rate private share (Privatanteil):

The private share of wages and car costs you charged to the business is added separately. Our article on private contributions and withdrawals explains how to book money moving between the business and your private finances correctly.

AHV belongs in the business result, pillar 3a doesn't

In St. Gallen, you deduct your personal AHV/IV/EO contributions as a business expense, directly in the result of Ziffer 2.1. Our article on AHV contributions for the self-employed explains how much they are.

Pillar 3a, on the other hand, counts as private pension provision for the self-employed too. It never goes in the income statement, only in Ziffer 13.1.

The same applies to buy-ins to the 2nd pillar (Ziffer 13.2). Of your own BVG contributions, only the "Arbeitgeberanteil" (employer's share) may go through the business, which is half if you have no staff.

According to the Federal Social Insurance Office (BSV/OFAS), these maximums apply for 2026: CHF 7,258 with a pension fund, and without a pension fund 20% of earned income, up to CHF 36,288. Only what was actually paid in during 2026 counts. Since 2026, you can also make up gaps from 2025 onwards. Our article on pillar 3a for the self-employed: 2026 maximum and back-payments shows how to work out your personal amount.

Depreciation

For depreciation on a laptop, machines or a vehicle, St. Gallen applies Merkblatt 18 (leaflet 18) on steuern.sg.ch. For other expenses you can deduct, see our overview of tax deductions for the self-employed.

What goes where in E-Tax SG?

The Ziffer numbers come from the 2025 Wegleitung (as of Nov 2026). Check the labels in your 2026 tax return.

E-Tax SG step by step

Here's how to work through your St. Gallen tax return as a self-employed person:

1. Log in via etax.sg.ch with your E-Login and the "AGOV access" app.
2. Open the 2026 tax return with your Register-Nr. and Zugangscode.
3. Carry over last year's data. Check what has changed since 2025.
4. Declare your self-employed activity and enter the profit in Ziffer 2.1.
5. Upload your statement or accounts. Up to 10 MB per file is allowed, 100 MB per tax return and no more than 100 documents. You can photograph paper receipts straight into the tax return with the free Snapshare app.
6. Check your deductions, especially 3a in Ziffer 13.1.
7. Look at the running tax calculation. It's a guide, not an assessment.
8. Submit (next section).

Submitting: fully digital or with a Freigabequittung

E-Tax SG offers two routes. With eFiling, you upload all your documents and submit everything digitally. You don't sign anything and don't have to go to the post office. After submitting, you have 72 hours to make corrections. After that, the tax return is automatically deemed filed.

If you don't upload any documents, E-Tax SG only submits the figures. You then print the Freigabequittung (release receipt), sign it and send it with your documents to your Gemeindesteueramt. A tax return created in E-Tax SG can't be printed out and filed by post.

This is where the biggest deadline trap lies. With a Freigabequittung, the tax return only counts as filed once the signed receipt reaches the Gemeindesteueramt. Clicking "Einreichen" (submit) is not enough.

Picture Reto, a fictional IT consultant from Rapperswil-Jona. He submits his figures on 28 March and puts the receipt on the pile to sign.

It sits there for three weeks. For the tax office, his tax return was therefore not filed on time, and he risks a reminder. With eFiling, he would have been done before 31 March.

If the submission fails with a "technische Störung beim Empfängersystem" (technical fault in the receiving system), the cause is usually a protected PDF. Check under File, Properties, Security whether there is a password or a signature. If so, open the document on screen, photograph it with Snapshare and upload the image again.

St. Gallen tax deadline extension: how to get more time

You request the extension online via the canton's Schalter E (e-services portal) or directly in E-Tax SG with the "Frist verlängern" (extend deadline) button. You need your Register-Nr. and date of birth. The request is approved or rejected immediately, and it's free.

Three rules to know:

• Before the deadline expires. A request after the date on page 1 is too late.
• Only with paid bills. According to the canton, an extension is only granted if the tax bills that are due have been paid.
• A sole proprietorship counts as a private individual. The rules for natural persons apply to you, not those for GmbHs and AGs (limited companies).

According to the Gemeindesteueramt, how long you can extend at most varies from case to case. The canton doesn't publish a fixed maximum date that applies to everyone. If you extend more than once, you have to give a reason. Without online access, you submit the request in writing to the Gemeindesteueramt.

If you still don't file despite a reminder, the 2025 Wegleitung (as of Nov 2026) says you face a fine (Busse) of usually at least CHF 250. On top of that, the tax office can assess you at its discretion.

After filing: adjust your provisional bill to your profit

For the self-employed, this is the real money question. St. Gallen sends the provisional bill for cantonal and municipal taxes at the start of the year, payable in three instalments: end of May, end of July and end of September. The provisional bill for the direct federal tax arrives in January of the following year and is due by the end of March.

These amounts are based on estimated figures. If your profit has changed a lot, you adjust the provisional bill via the canton's eServices. As a reference, use your year-to-date profit from Magic Heidi.

Paying early pays off a little. For cantonal and municipal taxes, the tax office credits you with an Ausgleichszins (compensatory interest) on payments made before the due date (31 July). From the due date onwards, it's charged on the amount you owe. Both are settled in the final bill.

For 2026, the Ausgleichszins is 0.25%, after 0.75% in 2025 (Steuerbuch StB 212 Nr. 1, the canton's tax manual). The rate for 2027 is set by the cantonal government.

An example: Sandra, a fictional yoga teacher in St. Gallen (figures for illustration), doubled her classes in 2026. Her provisional bill is still based on her old profit.

In May, she sees in Magic Heidi that her profit is about CHF 20,000 higher than the year before, and she increases the provisional bill online. That way, there's no big back-payment all at once the following year.

Common mistakes in the St. Gallen tax return for the self-employed

• Deducting 3a in the income statement instead of in Ziffer 13.1
• Forgetting the private share, even though electricity, internet or phone ran through the business
• Never sending the Freigabequittung, so the tax return counts as not filed
• Uploading protected PDFs, which makes the submission fail
• Requesting an extension too late or with tax bills still open

When a fiduciary makes sense

A fiduciary (Treuhänder) is worth it if you have significant depreciation, VAT liability, property in the business, a business start or a closure. In E-Tax SG, they open your tax return with your Register-Nr. and Zugangscode, or you share it with them via the share function. For that, you both need an E-Tax SG account. You can revoke access granted via the share function at any time.

Official links

The canton's pages are in German.

• E-Tax SG: information and FAQ (sg.ch)
• E-Tax SG help centre
• Deadline extension for private individuals (sg.ch)
• Wegleitung for the 2025 tax return, natural persons (PDF); the 2026 Wegleitung has not been published yet (as of November 2026)
• Paying taxes, provisional bill, Ausgleichszins (sg.ch)
• St. Gallen Steuerbuch (tax manual)
• E-Login support
• The third pillar (BSV)

Conclusion

With E-Tax SG, the St. Gallen tax return is quicker than it used to be, as long as your business figures are ready. Stick to four points. Your profit goes in Ziffer 2.1, and your statement or accounts get uploaded. AHV is part of the business result, and pillar 3a goes in Ziffer 13.1.

File via eFiling, or send the Freigabequittung straight away. And if you need more time, request the extension before the date on page 1.

The rest is preparation throughout the year. Record every invoice and every expense in Magic Heidi in 2027. Then next winter you'll export revenue, expenses and profit in minutes and start E-Tax SG with your figures ready. You can try Magic Heidi for free.