Self-employed on the side: what you need to know

Key points at a glance

AHV (old-age and survivors' insurance): If your net profit from the side activity is at most CHF 2'500 per year, the compensation office (Ausgleichskasse) collects contributions only if you request it (Art. 19 of the AHV Ordinance (AHVV), in German). Above that, you register as self-employed.
Taxes: You declare income from the side activity from the very first franc - less your business expenses.
VAT (MWST) and commercial register only become mandatory once revenue from your self-employed activity reaches CHF 100'000. Your salary does not count.
Employer: You must not compete with your employer (Art. 321a of the Swiss Code of Obligations (CO)). Check your employment contract for rules on secondary employment.

Side activity or hobby?

You are self-employed if you work in your own name and for your own account, bear the risk yourself and intend to make money. It doesn't matter if you only do this a few hours a week. A hobby where you occasionally sell something, on the other hand, is not a gainful activity - the compensation office and the tax office decide case by case, based on factors such as regularity, market presence and profit motive.

Important: whether you count as self-employed for AHV purposes is decided by the compensation office - not by you. If you work almost exclusively for a single client, follow their instructions and bear no business risk, it may classify you as an employee instead. Your client then has to account for the social security contributions.

AHV: the CHF 2'500 exemption limit

As an employee, you pay your AHV contributions through your salary. For the side activity, contributions are based on your net profit, i.e. income minus business expenses - not on revenue. If it is no more than CHF 2'500 per year (limit since January 1, 2025), the compensation office collects contributions only at your request (Art. 19 AHVV, see AHV/IV leaflet 2.02). Paying voluntarily can be worthwhile if you want to avoid contribution gaps.

If you earn more, you register as self-employed with the compensation office of your canton of residence. It calculates the contributions on your net profit - on a sliding scale for lower incomes, and at no more than 10%. Since your final profit is only known once your tax assessment is issued, you first pay provisional contributions based on an estimate, followed by a final settlement. So estimate realistically - a large back payment is no fun.

Example: IT specialist building websites in the evening

Lukas works full time (100%) as an IT specialist and builds websites on the side for clubs and small shops. In his first year he invoices CHF 18'000 and spends CHF 4'000 on software, a share of his laptop and training. His net profit of CHF 14'000 is clearly above the exemption limit: he registers with the compensation office as self-employed and declares the profit in his tax return. He is not subject to VAT and does not have to register in the commercial register (Handelsregister). He has informed his employer - and he does not work for his employer's customers.

Taxes: from the first franc

There is no exemption limit for taxes: you declare income from the side activity in your tax return as income from self-employment. You may deduct business-related expenses (Art. 27 of the Federal Act on Direct Federal Taxation (DBG), in German), such as materials, software, a share of your laptop, travel or a home office if it meets the requirements. You need receipts for this - and simple records of income, expenses and your financial position are enough (Art. 957 para. 2 CO).

If you only make losses over a longer period, the tax office may treat the activity as a hobby (Liebhaberei) and disallow the losses. So document how you find customers and how you plan to make money.

VAT and commercial register

Both thresholds refer only to revenue from your self-employed activity; your salary does not count:

VAT: Mandatory from CHF 100'000 in revenue from taxable supplies per year (Art. 10 para. 2 let. a of the Value Added Tax Act (VATA)); you would register online with the Federal Tax Administration FTA (ESTV). Below the threshold, you don't show any VAT. A note on your invoices such as "Not subject to VAT (Art. 10 para. 2 let. a VATA)" helps.
Commercial register: Mandatory from CHF 100'000 in revenue in the last financial year (Art. 931 CO, Art. 36 of the Commercial Register Ordinance (HRegV), in German); voluntary at any time. More on this in the guide Starting a sole proprietorship.

Your employer: duty of loyalty and employment contract

A side activity is generally allowed. While you are employed, however, you must not do paid work for third parties if this breaches your duty of loyalty, in particular if you compete with your employer (Art. 321a para. 3 CO). If you poach your employer's customers or compete with them directly, you risk being dismissed without notice.

Check the employment contract: Many contracts or staff regulations require you to report a secondary activity or get it approved.
Performance in the main job: Even a non-competing side activity must not affect your performance at work, for example because you are exhausted.
Vacation is for rest: If you do paid work for third parties during your vacation and this harms your employer's legitimate interests, your employer may withhold your vacation pay (Art. 329d para. 3 CO).
Company resources stay off-limits: Don't use your employer's laptop, software licenses or working time for your side activity.

Being open is easiest: a quick conversation with your manager clears things up and avoids misunderstandings.

Insurance and retirement savings

Accident: If you work at least 8 hours per week in your main job, you are also insured against non-occupational accidents (Suva page in German) through your employer. An accident during your self-employed side activity then counts as a non-occupational accident (Art. 8 of the Accident Insurance Act (UVG), in German) and is covered by your employer's accident insurance - as the Federal Supreme Court ruled in 2024 (BGE 150 V 391). However, daily allowances and pensions are based only on your salary from your job; this insurance does not cover lost earnings from the side activity. For that, you can take out voluntary insurance as a self-employed person (Art. 4 UVG) - with a private insurer or, depending on the industry, with Suva's insurance for entrepreneurs (in German).
Liability: For damage you cause to customers, you need business or professional liability insurance - personal liability insurance usually does not cover professional activities.
Pillar 3a: If you are insured with a pension fund (Pensionskasse) through your main job, the "small" maximum of CHF 7'258 applies to you (2026, key figures of the Federal Social Insurance Office FSIO (BSV), in German) - regardless of the side activity.

How it works in Easly

With a side business, time is short - the admin work should take just a few minutes. That's what Easly is built for:

Quote and QR-bill in minutes: With your logo and colors; one click turns the quote into an invoice, which goes straight to the customer by email from your own mailbox.
VAT note automatically: If you are not subject to VAT, every invoice carries the note referring to Art. 10 para. 2 let. a VATA.
Record receipts immediately: Snap a photo with your phone or forward by email; with your own AI access, Easly reads the amount, date and supplier.
Trips and office space: Log business trips with a suggested distance; Easly calculates the share of your home used as an office for each year.
Ready for the tax return: Income statement with drill-down to each receipt, mileage log, home office deduction and receipt archive as Excel and ZIP - for you or your accountant (Treuhand). Easly does not fill in the tax return itself.

Easly costs CHF 13.90 per month excluding VAT - with a 14-day money-back guarantee.

Easly dashboard with open tasks, revenue and notices

Frequently asked questions

Do I have to register a small side activity for AHV?

If your net profit from the side activity is no more than CHF 2'500 per year, the compensation office collects contributions only at your request (Art. 19 AHVV). If it is higher, you register as self-employed with the compensation office of your canton of residence.

Do I have to pay tax on income from the side activity?

Yes, from the very first franc. You declare it as income from self-employment and deduct your business-related expenses. For this, you need receipts and a simple record of income and expenses.

Do I have to inform my employer?

The law has no general duty to inform, but many employment contracts and staff regulations require you to report it or get approval. You must not compete with your employer while you are employed (Art. 321a para. 3 CO).

When do I have to charge VAT?

Only once you reach CHF 100'000 in revenue from taxable supplies per year - only revenue from your self-employed activity counts, not your salary (Art. 10 para. 2 let. a VATA).

Information as of: see above. Sources: AHV Ordinance (in German; Art. 19 AHVV, limit since January 1, 2025, see leaflet 2.02), Swiss Code of Obligations (Art. 321a, 329d, 931 and 957 CO), Commercial Register Ordinance (in German; Art. 36 HRegV), Federal Act on Direct Federal Taxation (in German; Art. 27 DBG), Value Added Tax Act (Art. 10 VATA), Accident Insurance Act (in German; Art. 4 and 8 UVG), Federal Supreme Court decision BGE 150 V 391 (2024). Whether you count as self-employed is decided by the compensation office. This article is not a substitute for advice from your compensation office, the tax office or your accountant.