Home›Blog›AHV
AHV

How to Correctly Calculate OASI Advance Payments as a Self-Employed Person

Calculating OASI advance payments as a self-employed person: Contribution rates, calculation example and tips to avoid back-payments.

e
einzly Redaktion
Tax & Finance Editorial
6 min read
3 Feb 2026

01What Are OASI Advance Payments?

As a self-employed person in Switzerland, you are required to pay your OASI/DI/IC (AHV/IV/EO) contributions yourself to the cantonal compensation fund. Unlike employees, whose employer deducts contributions monthly, you must actively manage the payments yourself.

The OASI advance payment is a provisional prepayment that you make quarterly. The amount is based on an estimate of your expected annual income. The compensation fund typically uses your last known income from the tax assessment for this purpose.

Once the definitive tax assessment is available, the final settlement is calculated. If you paid too little, a back-payment follows. If you paid too much, you receive a refund. The goal is therefore to keep the advance payment as close to your actual income as possible.

Good to knowThe OASI contributions simultaneously cover DI (Disability Insurance) and IC (Income Compensation). With a single contribution, you therefore pay into all three social insurance schemes.

02OASI Contribution Rates for the Self-Employed

Self-employed persons pay the entire OASI/DI/IC contribution on their own -- there is no employer share. In return, a declining scale (degressive contribution scale) applies: the lower your net income, the lower the percentage contribution rate.

The scale ranges from 5.371% at very low income to the maximum rate of 10.6% of net income from self-employment. The minimum contribution is CHF 514 per year (as of 2024/2025).

Net income (CHF)Contribution rate
up to 9,8005.371%
17,0005.509%
21,4005.786%
25,7006.062%
30,1006.339%
34,4006.615%
38,8006.892%
43,1007.168%
47,5007.445%
51,8007.721%
57,4008.274%
from 57,40010.6%
Net income = Revenue minus business expensesThe contribution rate is applied to your net income -- i.e. your revenue minus all business-related expenses. Do not confuse this with gross revenue.

03How to Calculate Your Advance Payment

Calculating your OASI advance payment involves three simple steps. You need a realistic estimate of your annual income.

  1. Estimate your annual net income. Take your expected revenue and deduct all business expenses (materials, rent, software, insurance, etc.). The result is your expected net income from self-employment.
  2. Determine the applicable contribution rate. Use the contribution scale from Section 2. For net income of CHF 57,400 or more, the maximum rate of 10.6% applies.
  3. Calculate the annual contribution and divide by 4. Multiply your estimated net income by the contribution rate. Divide the result by 4 to get the quarterly advance payment.

The compensation fund normally sets the advance payment based on your last tax assessment. If you know that your income has changed significantly, you should proactively request an adjustment. How to correctly complete your tax return as a sole proprietor is explained separately.

Do not forget the OASI contribution in your estimateYour OASI contribution itself is also a deductible expense. You may deduct half of the OASI contribution from your income before the contribution is calculated. In practice, the compensation fund applies this deduction automatically.

04Concrete Calculation Example

Let us assume you are a self-employed consultant with an estimated net income of CHF 80,000 per year. Here is how you calculate your OASI advance payment:

Estimated net income: CHF 80,000. Contribution rate (from CHF 57,400): 10.6%. Annual OASI/DI/IC contribution: CHF 80,000 x 10.6% = CHF 8,480. Advance payment per quarter: CHF 8,480 / 4 = CHF 2,120. You therefore pay approximately CHF 2,120 per quarter to your cantonal compensation fund.

If your income rises to CHF 95,000 by the end of the year, the difference will be claimed in the final settlement. In this case, that would be an additional CHF 1,590 (CHF 95,000 x 10.6% = CHF 10,070 minus CHF 8,480 already paid). To avoid this, adjust your advance payment in good time.

05Adjusting Your Advance Payment -- When and How

Your income as a self-employed person often fluctuates from year to year. If you notice that your current income differs significantly from the previous year, you should have your advance payment adjusted. This is easier than most people think.

Contact your cantonal compensation fund -- preferably in writing by email or via your fund's online portal. Share your new income estimate. The compensation fund will then adjust your quarterly advance payments accordingly.

  • Income rising? Increase the advance payment to avoid a large back-payment. Back-payments may be subject to default interest.
  • Income falling? Reduce the advance payment so you do not tie up capital unnecessarily. Refunds from the final settlement can take months.
  • Unchanged? Even if your income remains stable, an annual check is worthwhile.
No fixed deadline requiredYou can request an adjustment at any time during the current year. There is no special deadline for this -- the sooner, the better.

06Tips to Avoid Back-Payments

Back-payments on OASI contributions are annoying -- especially when they come unexpectedly. With these strategies, you can ensure your advance payment matches your actual income as closely as possible.

Tip 1: Build reservesSet aside approximately 10-11% of your net profit in a separate account with every invoice. That way you always have the OASI contributions ready -- even in case of a back-payment.
Tip 2: Review every six monthsCompare your income so far in June with your estimate. If it deviates by more than 20%, adjust the advance payment immediately.
Tip 3: Keep your books up to dateAnyone who records income and expenses on an ongoing basis always has an overview of their current net income. Tools like einzly do this automatically.
Caution: Default interestFor back-payments, the compensation fund charges default interest from the due date. The larger the difference, the higher the interest burden. Adjusting in good time saves real money.

07Frequently Asked Questions About OASI Advance Payments

Advance payments are due quarterly. The exact dates are set by your cantonal compensation fund -- usually at the end of March, June, September and December. You will receive a bill with a payment slip in good time.
If your definitive income is lower than the estimate, you will receive a refund of the overpaid contributions after the final settlement. The final settlement takes place once the tax assessment is available -- this can take 1-2 years.
Yes. If your income changes significantly, you can request an adjustment of your advance payments from your compensation fund at any time. This is usually possible by email, telephone or via the compensation fund's online portal.
The minimum contribution for self-employed persons is CHF 514 per year (as of 2024/2025). This applies to very low net income and is payable quarterly in instalments of approximately CHF 129. The minimum contribution covers OASI, DI and IC.
Share