Quellensteuer Schweiz — A complete guide for expats

If you've moved to Switzerland on a B permit, your employer is almost certainly already deducting Quellensteuer from your salary. This guide explains what that is, why it matters, and how the subsequent ordinary assessment (NOV) can change the bill.

What is Quellensteuer?

Quellensteuer — literally "tax at source" — is a withholding tax deducted directly from your salary by your employer and paid to the cantonal tax authority. It applies to foreign workers without a settlement (C) permit, including most expats on B and L permits, and to cross-border (G) commuters.

The withheld amount bundles together federal, cantonal and communal income tax, plus church tax where applicable. The rate depends on your canton of residence (or work, for cross-border workers), your gross income, your family situation, and any second income or special circumstances.

Who pays Quellensteuer?

• Foreign nationals resident in Switzerland without a C permit (typically B and L permits).
• Cross-border commuters (G permit) working in Switzerland but living in a neighbouring country.
• Short-term or non-resident workers receiving Swiss-source income.

You stop being subject to Quellensteuer once you receive a C permit, marry a Swiss citizen or C-permit holder, or become a Swiss citizen. From that point you file an ordinary tax return like any other resident.

The subsequent ordinary assessment (NOV)

The "nachträgliche ordentliche Veranlagung" (NOV) — the subsequent ordinary assessment — is the process by which your Quellensteuer is recalculated against a full Swiss tax return. There are two paths into it.

Mandatory NOV

If your gross annual employment income exceeds CHF 120,000 (CHF 500,000 in Geneva), you are required to file a full Swiss tax return. The Quellensteuer already deducted is credited against your actual liability; you pay any shortfall or receive any refund.

Voluntary NOV on request

Below the threshold, you can request a subsequent ordinary assessment by 31 March of the year following the tax year. This is worth doing if you have deductible expenses the Quellensteuer rate does not account for — pillar 3a contributions, pension buy-ins (Einkauf), training costs, alimony, childcare, mortgage interest, or significant medical bills.

When is requesting the NOV worth it?

As a rough rule of thumb, the NOV is usually beneficial when you have:

• Maximum pillar 3a contributions (currently CHF 7,258 for employed individuals).
• A pension buy-in (Einkauf in die Pensionskasse) of any meaningful size.
• Mortgage interest on a primary residence you own.
• Substantial professional training costs you paid yourself.
• Out-of-pocket medical expenses above the cantonal threshold.

It is usually not worth it if you have no significant deductions and your circumstances will not change — the ordinary process is more work, locks you in, and may slightly increase your bill in low-tax communes.

Common mistakes

• Missing the 31 March deadline to request the NOV.
• Forgetting that the choice is irreversible while you remain on a B permit.
• Failing to declare worldwide income and assets once you file an ordinary return — even foreign property and bank accounts must be disclosed.
• Assuming Quellensteuer covers everything: church tax may apply separately, and second incomes (freelance, rental) almost always trigger an additional filing.
• Overlooking treaty relief on foreign-source income that is already taxed abroad.

Get this right with a vetted advisor

The Quellensteuer-to-NOV transition is one of the most common reasons expats overpay tax in their first few years in Switzerland. A specialist who handles expat cases regularly can model your situation in an hour and tell you whether to opt in.