CH Federal Income Tax

Switzerland Federal Income Tax (Direkte Bundessteuer) -- Self-Employed Skill v2.0

Section 1 -- Quick Reference

Quick Reference

Field	Value
Country	Switzerland (Federal level only)
Tax	Direkte Bundessteuer (DBSt)
Currency	CHF only
Tax year	Calendar year
Primary legislation	Bundesgesetz uber die direkte Bundessteuer (DBG), SR 642.11
Supporting legislation	AHVG; BVG; BVV 3
Tax authority	ESTV / AFC
Filing portal	Cantonal tax portal (varies -- federal filed with cantonal return)
Filing deadline	31 March (standard, varies by canton) / extensions routinely available
Contributor	Open Accountants Community
Validated by	Pending -- requires sign-off by Swiss Treuhnder or Steuerberater
Validation date	Pending
Skill version	2.0

IMPORTANT: This skill covers FEDERAL tax only. Cantonal and municipal taxes are separate and typically represent the majority of the total tax burden. They are out of scope.

Federal Tax Tariff -- Grundtarif (Single) -- Approximate

Federal Tax Tariff -- Grundtarif (Single) -- Approximate

Taxable Income (CHF)	Approx. Marginal Rate
0 -- 17,800	0%
17,801 -- 31,600	0.77%
31,601 -- 41,400	0.88% -- 2.64%
41,401 -- 55,200	2.97%
55,201 -- 72,500	5.94%
72,501 -- 78,100	6.60%
78,101 -- 103,600	8.80%
103,601 -- 134,600	11.00%
134,601 -- 176,000	13.20%
176,001+	11.50% max effective rate

• Never compute from approximate brackets — NEVER compute Swiss federal tax from these approximate brackets. Use official ESTV tariff tables.

Verheiratetentarif (Married)

More favourable. Tax-free threshold ~CHF 30,800. Maximum effective rate 11.5% reached ~CHF 912,600.

Saule 3a Limits (2025)

Saule 3a Limits (2025)

Category	Maximum (CHF)
With BVG (Pensionskasse)	7,258
Without BVG	20% of net earned income, max 36,288

AHV/IV/EO (Self-Employed)

AHV/IV/EO (Self-Employed)

Component	Rate
Total AHV/IV/EO	10.0%

• AHV/IV/EO deductibility — Fully deductible. Rate 10.0% on income above CHF 10,100 (declining scale below).

Key Deduction Lines

Key Deduction Lines

Line	Description
Geschaftsaufwand	Business expenses
Abschreibungen	Depreciation
AHV/IV/EO	Social insurance contributions
BVG	Pillar 2 pension
Saule 3a	Pillar 3a
Kinderabzug	CHF 6,700 per child

Conservative Defaults

Conservative Defaults

Ambiguity	Default
Unknown marital status	STOP -- determines tariff
Unknown BVG status	Without BVG (higher 3a limit applies)
Unknown business-use %	0% deduction
Unknown expense category	Not deductible
Unknown cantonal question	ESCALATE -- federal only

Section 2 -- Required Inputs and Refusal Catalogue

Required Inputs

• Minimum viable inputs — Minimum viable -- bank statement for the full tax year, marital status, canton of residence.
• Recommended inputs — Recommended -- all invoices, AHV/IV/EO contribution statements, BVG certificate, Saule 3a statements, prior year Steuerveranlagung.
• Ideal inputs — Ideal -- complete business accounts, Anlageverzeichnis, provisional tax notices.
• Refusal if minimum missing — Refusal if minimum is missing -- SOFT WARN. No bank statement = hard stop. Unknown marital status = hard stop.

Refusal Catalogue

• R-CH-1 — Cantonal / municipal tax. "This skill covers FEDERAL tax only. Cantonal and municipal taxes require separate cantonal skills or Treuhnder consultation. Do not estimate."
• R-CH-2 — Corporations (AG, GmbH, Verein). "Corporate taxation is separate. Out of scope."
• R-CH-3 — Non-resident / Quellensteuer. "Source tax for non-residents has different rules. Escalate."
• R-CH-4 — Interkantonale Steuerausscheidung. "Multi-canton allocation is out of scope."
• R-CH-5 — Steuererlass / tax relief applications. "Escalate to Treuhnder."

Section 3 -- Transaction Pattern Library

This is the deterministic pre-classifier. When a bank statement transaction matches a pattern below, apply the treatment directly. If none match, fall through to Tier 1 rules in Section 5.

3.1 Income Patterns (Credits)

3.1 Income Patterns (Credits)

Pattern	Tax Line	Treatment	Notes
ZAHLUNG, UBERWEISUNG [client], HONORAR	Einkünfte selbstandige Erwerbstatigkeit	Business income	Extract net if MWST-registered
STRIPE PAYOUT, PAYPAL PAYOUT	Business income	Revenue	Platform payout
LOHN, GEHALT, ARBEITGEBER	Einkünfte unselbstandige Erwerbstatigkeit	NOT self-employment	Employment income
MIETEINNAHME, MIETZINS	Einkünfte Liegenschaft	NOT self-employment	Rental income
ZINSEN, KAPITALERTRAG, DIVIDENDE	Einkünfte Vermogen	NOT self-employment	Capital income (VSt 35%)
STEUERRUCKERSTATTUNG, RUCKZAHLUNG	EXCLUDE	Not income	Tax refund

3.2 Expense Patterns (Debits) -- Fully Deductible (Geschaftsaufwand)

3.2 Expense Patterns (Debits) -- Fully Deductible (Geschaftsaufwand)

Pattern	Category	Treatment	Notes
BÜROMIETE, GESCHÄFTSMIETE, OFFICE RENT	Raumkosten	Fully deductible	Dedicated premises
BERUFSHAFTPFLICHT, VERSICHERUNG (business)	Versicherung	Fully deductible	Professional insurance
TREUHAND, BUCHHALTER, STEUERBERATER	Beratungskosten	Fully deductible
RECHTSANWALT, NOTAR (business)	Rechtskosten	Fully deductible
BÜROMATERIAL	Bürobedarf	Fully deductible
WERBUNG, MARKETING, GOOGLE ADS	Werbekosten	Fully deductible
WEITERBILDUNG, KURS, SEMINAR	Weiterbildung	Fully deductible (up to CHF 12,900)	Job-related
VERBANDSBEITRAG, MITGLIEDSCHAFT	Beitrge	Fully deductible	Professional associations
BANKGEBÜHR, KONTOFÜHRUNG	Bankspesen	Fully deductible	Business account
STRIPE FEE, PAYPAL FEE	Transaktionskosten	Fully deductible
SOFTWARE, LIZENZ, ABONNEMENT (under CHF 1,000)	IT-Kosten	Fully deductible	Low-value = immediate expense

3.3 Expense Patterns -- Social Insurance

3.3 Expense Patterns -- Social Insurance

Pattern	Treatment	Notes
AHV, AUSGLEICHSKASSE, SVA	Fully deductible	AHV/IV/EO contributions
BVG, PENSIONSKASSE, AUFFANGEINRICHTUNG	Fully deductible	Pillar 2
SÄULE 3A, VORSORGE 3A	Deductible within limits	CHF 7,258 or CHF 36,288

3.4 Expense Patterns -- Travel

3.4 Expense Patterns -- Travel

Pattern	Category	Treatment	Notes
FLUG, SWISS, EASYJET, RYANAIR	Reisekosten	Fully deductible	Business purpose
HOTEL, BOOKING.COM	Reisekosten	Fully deductible	Business travel
SBB, BLS, ZVV	Reisekosten	Fully deductible	Business travel
TAXI, UBER	Reisekosten	Fully deductible	Business purpose
TANKSTELLE, MIGROL, COOP PRONTO, BP	Fahrzeugkosten	T2 -- business % only

3.5 Expense Patterns -- NOT Deductible

3.5 Expense Patterns -- NOT Deductible

Pattern	Treatment	Notes
PRIVAT, LEBENSMITTEL, MIGROS, COOP (groceries)	NOT deductible	Lebenshaltungskosten
BUSSE, ORDNUNGSBUSSE	NOT deductible	Fines
BUNDESSTEUER, KANTONSSTEUER, STEUERN	NOT deductible	Income tax
PRIVATBEZUG	NOT deductible	Drawings

3.6 Capital Items

3.6 Capital Items

Pattern	Straight-Line	Reducing Balance	Notes
COMPUTER, LAPTOP, PC	40%	50%
BÜROMÖBEL	12.5%	25%
FAHRZEUG, AUTO (business)	20%	40%
MASCHINE, EQUIPMENT	12.5%-20%	25%-40%
GEBÄUDE (commercial)	2%-4%	3%-7%
Low-value (under CHF 1,000)	100% immediate	--

3.7 Exclusions

3.7 Exclusions

Pattern	Treatment	Notes
EIGENÜBERWEISUNG, INTERNAL	EXCLUDE	Own-account transfer
DARLEHEN, KREDIT, AMORTISATION	EXCLUDE	Loan principal
DARLEHENSZINS (business)	Deductible	Business loan interest
MWST ZAHLUNG	EXCLUDE from P&L	MWST liability
STEUERZAHLUNG	EXCLUDE	Tax payment

3.8 Swiss Banks -- Statement Format Reference

3.8 Swiss Banks -- Statement Format Reference

Bank	Format	Key Fields	Notes
UBS	CSV, PDF, MT940	Buchungsdatum, Text, Betrag	UBS e-banking export
PostFinance	CSV, PDF	Datum, Buchungstext, Gutschrift/Belastung	PostFinance e-Finance
ZKB (Zurcher Kantonalbank)	CSV, PDF	Datum, Text, Betrag
Credit Suisse / UBS (merged)	CSV, PDF	Datum, Beschreibung, Betrag	Post-merger formats
Raiffeisen CH	CSV, PDF	Datum, Buchungstext, Betrag
Revolut, Wise	CSV	Date, Counterparty, Amount	Multi-currency

Section 4 -- Worked Examples

Example 1 -- Client Payment (MWST-registered)

Input line: 15.03.2025 ; UBS Gutschrift ; AGENTUR ZURICH AG ; Honorar Mrz 2025 ; +8,100.00 ; CHF

Reasoning: Client payment. If MWST-registered (8.1% standard rate), CHF 8,100 may include MWST. Check invoice: if gross, net = CHF 7,493.06 + CHF 606.94 MWST. If Kleinunternehmer, full CHF 8,100.

Classification: Business income = CHF 7,493.06 (or CHF 8,100 if not MWST-registered).

Example 2 -- AHV Contribution

Input line: 15.02.2025 ; PostFinance Belastung ; AUSGLEICHSKASSE ZURICH ; AHV/IV/EO ; -4,800.00 ; CHF

Reasoning: AHV/IV/EO contributions. Fully deductible from taxable income.

Classification: Deductible. Reduces taxable income.

Example 3 -- Saule 3a Contribution

Input line: 30.06.2025 ; ZKB Überweisung ; CREDIT SUISSE SÄULE 3A ; Einzahlung 2025 ; -7,258.00 ; CHF

Reasoning: Saule 3a at maximum (CHF 7,258 with BVG). Fully deductible.

Classification: Deductible (within limit). If without BVG, could be up to CHF 36,288.

Example 4 -- Software Subscription

Input line: 01.04.2025 ; UBS Lastschrift ; ADOBE INC ; Creative Cloud ; -35.90 ; CHF

Reasoning: Monthly SaaS subscription. Under CHF 1,000. Fully deductible as Geschaftsaufwand.

Classification: Geschaftsaufwand -- IT. Fully deductible.

Example 5 -- Cantonal Tax Payment (Exclude)

Input line: 30.09.2025 ; PostFinance ; STEUERAMT ZH ; Kantonssteuer 2025 ; -5,000.00 ; CHF

Reasoning: Tax payment. Not deductible. Not a business expense.

Classification: EXCLUDE. Not deductible.

Example 6 -- Low-Value Asset

Input line: 03.06.2025 ; UBS Karte ; DIGITEC ; Drucker ; -890.00 ; CHF

Reasoning: Printer CHF 890. Under CHF 1,000 low-value threshold. Immediate full deduction.

Classification: Geschaftsaufwand. Fully deductible in year of purchase.

Section 5 -- Tier 1 Rules (When Data Is Clear)

5.1 Business Income

• Business income treatment — All self-employment income is Einkünfte aus selbstandiger Erwerbstatigkeit (Art. 18 DBG). For MWST-registered, report net. (Art. 18 DBG)

5.2 Geschaftsaufwand

• Business expense deductibility — Business expenses deductible under DBG Art. 27-31. Must be business-related. (DBG Art. 27-31)

5.3 Abschreibungen (Depreciation)

• Depreciation method — Choose straight-line or reducing balance (consistent per asset). ESTV guideline rates apply. Low-value under CHF 1,000 may be expensed immediately.

5.4 AHV/IV/EO Deductibility

• AHV/IV/EO deductibility detail — Fully deductible. Self-employed pay 10.0% on income above CHF 10,100 (declining scale below). Circular calculation resolved by Ausgleichskasse.

5.5 Saule 3a and BVG

• Saule 3a and BVG limits — - With BVG: max CHF 7,258 - Without BVG: 20% of net earned income, max CHF 36,288 - Hard cap -- excess not deductible

5.6 Personal Deductions (Federal)

5.6 Personal Deductions (Federal)

Deduction	CHF
Married couple	2,800
Kinderabzug	6,700 per child
Unterstützungsabzug	Up to 7,050

5.7 Non-Deductible

5.7 Non-Deductible

Expense	Reason
Personal living expenses	Art. 34 DBG
Fines (Bussen)	Public policy
Income tax (all levels)	Tax on income
Capital expenditure	Through Abschreibungen

5.8 Filing and Penalties

5.8 Filing and Penalties

Item	Detail
Standard deadline	31 March (varies by canton)
Extensions	Routinely available
Late filing	Reminder + fee; estimated assessment
Persistent non-filing	Fine up to CHF 1,000
Tax evasion	33.3%-300% of evaded tax

5.9 Provisional Tax

• Provisional tax billing — Billed by canton based on prior assessment. Interest on under/overpayment (Ausgleichszins).

Section 6 -- Tier 2 Catalogue (Reviewer Judgement Required)

6.1 Home Office (Arbeitszimmer)

• Home office deductibility — Deductible if predominantly business use AND no separate business premises. Proportion by floor area. Flag for reviewer.

6.2 Vehicle Business Use

• Vehicle business use split — Business vs private split required. Private use of business vehicle = taxable benefit (Naturallohn). Flag for reviewer.

6.3 Phone / Internet Mixed Use

• Phone/internet mixed use default — Business portion only. Default 0%.

6.4 BVG Voluntary Contributions

• BVG voluntary contributions — Self-employed may voluntarily join BVG. Contributions fully deductible. Flag for reviewer to confirm BVG status.

6.5 AHV Declining Scale

• AHV declining scale — For income CHF 10,100-58,800, rate is less than 10%. Use official AHV table.

Section 7 -- Excel Working Paper Template

SWITZERLAND FEDERAL INCOME TAX -- WORKING PAPER
Tax Year: 2025
Client: ___________________________
Marital Status: Single / Married
Canton: ___________ (for filing only -- cantonal tax is OUT OF SCOPE)

A. SELF-EMPLOYMENT INCOME
  A1. Business revenue (net of MWST)              ___________
  A2. Other business income                        ___________
  A3. Total                                        ___________

B. GESCHÄFTSAUFWAND
  B1. Raumkosten                                   ___________
  B2. Versicherungen (business)                    ___________
  B3. Beratungskosten                              ___________
  B4. IT / Software                                ___________
  B5. Marketing                                    ___________
  B6. Reisekosten                                  ___________
  B7. Fahrzeugkosten (business %)                  ___________
  B8. Abschreibungen                               ___________
  B9. Bankspesen                                   ___________
  B10. Übrige Geschäftsaufwand                     ___________
  B11. Total                                       ___________

C. NET SELF-EMPLOYMENT INCOME (A3 - B11)           ___________

D. DEDUCTIONS
  D1. AHV/IV/EO                                    ___________
  D2. BVG                                          ___________
  D3. Säule 3a                                     ___________
  D4. Kinderabzug                                  ___________
  D5. Other personal deductions                    ___________
  D6. Total deductions                             ___________

E. STEUERBARES EINKOMMEN (C - D6)                  ___________

F. DIREKTE BUNDESSTEUER (use ESTV tariff)          ___________

NOTE: This is FEDERAL TAX ONLY. Cantonal/municipal = separate.

REVIEWER FLAGS:
  [ ] Marital status confirmed (Grundtarif/Verheiratetentarif)?
  [ ] BVG status confirmed (affects Säule 3a limit)?
  [ ] Home office eligibility confirmed?
  [ ] Vehicle business % confirmed?
  [ ] AHV contribution rate confirmed (declining scale)?

Section 8 -- Bank Statement Reading Guide

Swiss Bank Statement Formats

Swiss Bank Statement Formats

Bank	Format	Key Fields	Notes
UBS	CSV, PDF, MT940	Buchungsdatum, Text, Betrag	E-banking export
PostFinance	CSV, PDF	Datum, Buchungstext, Gutschrift/Belastung	E-Finance export
ZKB	CSV, PDF	Datum, Text, Betrag
Raiffeisen CH	CSV, PDF	Datum, Buchungstext, Betrag
Credit Suisse (now UBS)	CSV, PDF	Datum, Beschreibung, Betrag	Legacy format
Revolut, Wise	CSV	Date, Counterparty, Amount	Multi-currency

Key Swiss Banking Terms

Key Swiss Banking Terms

Term	English	Hint
Gutschrift	Credit	Potential income
Belastung / Lastschrift	Debit	Potential expense
Überweisung	Transfer	Check direction
Dauerauftrag	Standing order	Regular expense
Kartenzahlung	Card payment	Expense
Bargeldbezug	Cash withdrawal	Ask purpose
Kontoführung	Account maintenance	Bank charge
Vergütung	Payment/remuneration	Often income

Section 9 -- Onboarding Fallback

ONBOARDING QUESTIONS -- SWITZERLAND FEDERAL INCOME TAX
1. Marital status: single or married?
2. Canton and municipality of residence?
3. BVG (Pensionskasse) member? (Affects Säule 3a limit)
4. Säule 3a contributions made?
5. Home office: dedicated room? Separate business premises?
6. Vehicle: business use %?
7. Phone/internet: business use %?
8. AHV/IV/EO contributions paid?
9. Other income (employment, rental, securities)?
10. Children / dependants?

Section 10 -- Reference Material

Key Legislation

Key Legislation

Topic	Reference
Self-employment income	DBG Art. 18
Business expenses	DBG Art. 27-31
Non-deductible	DBG Art. 34
Depreciation	DBG Art. 28; ESTV Merkblatt
AHV/IV/EO deduction	DBG Art. 33 Abs. 1 lit. d, f
BVG / Saule 3a	BVG; BVV 3; DBG Art. 33
Federal tariff	DBG Art. 214
Personal deductions	DBG Art. 33, 33a, 35
Filing	DBG Art. 124
Penalties	DBG Art. 175 (evasion: 33.3%-300%)

Test Suite

Test 1 -- Single, federal only. Input: Single, net income CHF 100,000, AHV CHF 10,000, Saule 3a CHF 7,258 (has BVG). Expected: Taxable CHF 82,742. Apply Grundtarif. Federal tax ~CHF 3,500-4,000.

Test 2 -- Married, joint. Input: Married, combined CHF 180,000, AHV CHF 12,000, Saule 3a CHF 14,516 total, 2 children. Expected: Taxable ~CHF 140,084. Apply Verheiratetentarif.

Test 3 -- Saule 3a without BVG. Input: Without BVG, net earned income CHF 200,000. Expected: Max 20% = CHF 40,000 but capped CHF 36,288.

Test 4 -- Saule 3a without BVG, income cap. Input: Without BVG, net earned CHF 30,000. Expected: 20% x CHF 30,000 = CHF 6,000.

Test 5 -- Low-value asset. Input: CHF 900 printer. Expected: Immediate expense.

Test 6 -- Cantonal question. Input: "How much tax in Zurich?" Expected: ESCALATE. Federal only.

PROHIBITIONS

• Prohibitions list — - NEVER compute Swiss federal tax from approximate brackets -- use ESTV tariff tables - NEVER apply Grundtarif to married or Verheiratetentarif to single - NEVER estimate cantonal or municipal taxes -- FEDERAL ONLY - NEVER allow Saule 3a above applicable maximum - NEVER allow income tax as a deduction - NEVER allow fines as deductions - NEVER allow capital expenditure directly as expense - NEVER present federal tax as total tax burden - NEVER present calculations as definitive

Disclaimer

This skill and its outputs are provided for informational and computational purposes only and do not constitute tax, legal, or financial advice. Open Accountants and its contributors accept no liability for any errors, omissions, or outcomes arising from the use of this skill. All outputs must be reviewed and signed off by a qualified professional (such as a Treuhnder or equivalent licensed practitioner in your jurisdiction) before filing or acting upon.

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