# rel.tax — Multi-Country B2B Tax Calculator API

> Free, open-source API for calculating self-employed and contractor taxes across 55 countries. No auth. No rate limits. CORS enabled.

Base URL: https://rel.tax

## Endpoints

- GET /v1/calculate/:country?params — Calculate taxes (query params)
- POST /v1/calculate/:country — Calculate taxes (JSON body)
- GET /v1/countries — List supported countries with currency codes
- GET /v1/countries/:country — Country-specific docs (JSON)
- GET /openapi.json — OpenAPI 3.1 specification (full)
- GET /openapi-slim.json — OpenAPI 3.1 specification (slim, for AI agents)
- GET /.well-known/ai-plugin.json — AI plugin manifest
- MCP Server: npx @sliday/reltax — native tools for Claude Desktop/Code

## Quick Start

```
curl "https://rel.tax/v1/calculate/de?income=60000"
```

Only `income` is required. All other parameters have sensible defaults.

---

## Countries

### PL — Poland (Tax Year 2026) | Currency: PLN
Polish B2B Tax Calculator (ZUS, health insurance, PIT)
Example: GET /v1/calculate/pl?income=10000&taxationType=lumpsum&lumpSumRate=12

Parameters:
- income (number, required): Gross income in PLN
- incomePeriod (string): (default: "monthly") Options: monthly, yearly
- taxationType (string): (default: "lumpsum") Options: lumpsum, linear, scale
- lumpSumRate (number): (default: 12) Options: 2, 3, 5.5, 8.5, 10, 12, 14, 15, 17
- zusRate (string): (default: "normal") Options: normal, preferential, start, none
- sickInsurance (boolean): Include chorobowe (2.45%) (default: false)
- costs (number): Monthly business costs PLN (default: 0)
- paidDaysOff (number): Vacation days/year (default: 26)
- weeklyHours (number): Weekly working hours (default: 40)
- zusBase (number): ZUS base as % of avg salary (default: 60)
- sickDays (number): Days on sick leave (default: 0)
- vatPayer (boolean): Include VAT calculation (default: true)

### NZ — New Zealand (Tax Year 2026) | Currency: NZD
New Zealand PAYE, ACC, KiwiSaver Calculator
Example: GET /v1/calculate/nz?income=75000

Parameters:
- income (number, required): Gross income NZD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- kiwiSaverRate (number): (default: 3) Options: 0, 3, 4, 6, 8, 10
- studentLoan (boolean): Has student loan (default: false)
- acc (boolean): Include ACC earners' levy (1.67%) (default: true)
- gstRegistered (boolean): GST registered (15%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### AU — Australia (Tax Year 2026) | Currency: AUD
Australian Income Tax, Medicare, HELP/HECS Calculator
Example: GET /v1/calculate/au?income=100000

Parameters:
- income (number, required): Taxable income AUD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- helpDebt (boolean): Has HELP/HECS student loan (default: false)
- medicareLevyExempt (boolean): Full Medicare levy exemption (default: false)
- privateHealth (boolean): Has private hospital cover (default: false)
- superRate (number): Self-funded super % (0 = employer default 12%) (default: 0)
- gstRegistered (boolean): GST registered (10%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### GB — United Kingdom (Tax Year 2026) | Currency: GBP
UK Self-Employed Income Tax, Class 4 NIC, Student Loan Calculator
Example: GET /v1/calculate/gb?income=50000

Parameters:
- income (number, required): Annual gross income GBP
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- region (string): (default: "england") Options: england, scotland
- studentLoan (string): (default: "none") Options: none, plan1, plan2, plan4, plan5, postgrad
- vatRegistered (boolean): VAT registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 28)

### US — United States (Tax Year 2025) | Currency: USD
US Federal Self-Employment Tax & Income Tax Calculator (Single Filer)
Example: GET /v1/calculate/us?income=100000

Parameters:
- income (number, required): Net self-employment income USD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- filingStatus (string): (default: "single") Options: single
- qbiDeduction (boolean): Apply QBI deduction (20%) (default: true)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### CA — Canada (Tax Year 2025) | Currency: CAD
Canadian Federal + Provincial Self-Employed Tax Calculator (CPP, EI, Income Tax)
Example: GET /v1/calculate/ca?income=100000&province=ON

Parameters:
- income (number, required): Net self-employment income CAD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- province (string): (default: "ON") Options: ON, BC, AB, QC, MB, SK, NS, NB, PE, NL, YT, NT, NU
- eiOptIn (boolean): Opted into EI (maternity/compassionate only) (default: false)
- gstRegistered (boolean): GST/HST registered (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### DE — Germany (Tax Year 2025) | Currency: EUR
German Income Tax (Einkommensteuer), Solidarity Surcharge, Church Tax, Social Insurance Calculator
Example: GET /v1/calculate/de?income=60000

Parameters:
- income (number, required): Annual gross income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- churchTax (string): Church tax rate: 8% (BW/BY) or 9% (other states) (default: "none") Options: none, 8, 9
- hasChildren (boolean): Has children (affects Pflegeversicherung rate) (default: true)
- healthInsurance (string): Health insurance type (default: "statutory") Options: statutory, none
- zusatzbeitrag (number): GKV supplementary rate % (default: 2.5)
- pensionInsurance (boolean): Voluntary pension insurance (default: false)
- gewerbesteuer (boolean): Subject to trade tax (Gewerbetreibende) (default: false)
- hebesatz (number): Municipal trade tax multiplier % (default: 400)
- vatRegistered (boolean): VAT registered (19%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 30)

### ES — Spain (Tax Year 2025) | Currency: EUR
Spanish IRPF (Income Tax), Autonomo Social Security (RETA) Calculator
Example: GET /v1/calculate/es?income=40000

Parameters:
- income (number, required): Annual gross income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses EUR (default: 0)
- newAutonomo (boolean): New autonomo (tarifa plana SS + 20% IRPF reduction) (default: false)
- vatRegistered (boolean): IVA registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 22)

### RS — Serbia (Tax Year 2025) | Currency: EUR
Serbian self-employed tax calculator: Preduzetnik (lična zarada) and Paušalac (lump-sum)
Example: GET /v1/calculate/rs?income=60000

Parameters:
- income (number, required): Annual gross income
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- currency (string): Input/output currency (default: "EUR") Options: EUR, RSD
- expenses (number): Annual deductible expenses (preduzetnik only) (default: 0)
- taxModel (string): Tax model (default: "preduzetnik") Options: preduzetnik, pausalac
- pausalnaOsnovica (number): Monthly lump-sum base in RSD (required for pausalac) (default: 0)
- vatRegistered (boolean): PDV registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### JP — Japan (Tax Year 2025) | Currency: JPY
Japan Self-Employed Tax Calculator (Income Tax, Resident Tax, Business Tax, NHI, National Pension)
Example: GET /v1/calculate/jp?income=5000000

Parameters:
- income (number, required): Annual gross business income JPY
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses JPY (default: 0)
- blueReturn (string): Blue return deduction tier (default: "full") Options: full, paper, basic, none
- businessTaxRate (number): Business tax rate % (default: 5) Options: 3, 4, 5
- nhiRate (number): NHI income-based rate % (varies by municipality) (default: 10)
- consumptionTax (boolean): Consumption tax registered (10%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

### EE — Estonia (Tax Year 2026) | Currency: EUR
Estonian FIE: Income Tax, Social Tax, II Pillar Pension
Example: GET /v1/calculate/ee?income=60000

Parameters:
- income (number, required): Gross business income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- pensionPillarRate (number): (default: 2) Options: 0, 2, 4, 6
- vatRegistered (boolean): VAT registered (22%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### GE — Georgia (Tax Year 2025) | Currency: GEL
Georgian Tax: SBS Turnover Tax or Regular Income Tax, Mandatory Pension
Example: GET /v1/calculate/ge?income=100000

Parameters:
- income (number, required): Gross business income GEL
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxRegime (string): Small Business Status or regular (default: "sbs") Options: sbs, regular
- expenses (number): Business expenses GEL (regular regime only) (default: 0)
- vatRegistered (boolean): VAT registered (18%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### AM — Armenia (Tax Year 2025) | Currency: AMD
Armenian Tax: Turnover Tax (IT 1%, General 10%), Regular Income Tax 20%, Social Payments
Example: GET /v1/calculate/am?income=50000000&taxRegime=turnover_it

Parameters:
- income (number, required): Gross business income AMD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- currency (string): Currency label (no conversion) (default: "AMD") Options: AMD, USD
- taxRegime (string): (default: "turnover_it") Options: turnover_it, turnover_general, regular
- expenses (number): Deductible expenses (regular regime only) (default: 0)
- vatRegistered (boolean): VAT registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### MX — Mexico (Tax Year 2025) | Currency: MXN
Mexican freelancer: RESICO or General ISR, optional IMSS, IVA
Example: GET /v1/calculate/mx?income=300000

Parameters:
- income (number, required): Gross business income MXN
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxRegime (string): (default: "resico") Options: resico, general
- expenses (number): Deductible expenses (general regime only) (default: 0)
- imssOptIn (boolean): Voluntary IMSS social security (default: false)
- vatRegistered (boolean): IVA registered (16%) (default: true)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

### PT — Portugal (Tax Year 2025) | Currency: EUR
Portuguese Freelancer: IRS, Solidarity Surcharge, Social Security (Seguranca Social)
Example: GET /v1/calculate/pt?income=60000

Parameters:
- income (number, required): Gross business income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- activityType (string): (default: "services_listed") Options: services_listed, services_other, sales
- expenses (number): Business expenses (organized regime only) (default: 0)
- accountingRegime (string): (default: "simplified") Options: simplified, organized
- newFreelancer (boolean): First 12 months: SS exempt (default: false)
- vatRegistered (boolean): IVA registered (23%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 22)

### NL — Netherlands (Tax Year 2026) | Currency: EUR
Dutch ZZP: Box 1 Income Tax, Zelfstandigenaftrek, MKB-vrijstelling, ZVW
Example: GET /v1/calculate/nl?income=60000

Parameters:
- income (number, required): Gross business profit EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- starter (boolean): First 3 of 5 years as entrepreneur (default: false)
- hoursExempt (boolean): True if NOT meeting 1225 hours criterion (default: false)
- vatRegistered (boolean): BTW registered (21%) (default: true)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### BG — Bulgaria (Tax Year 2025) | Currency: BGN
Bulgarian freelancer/sole trader: Income Tax, Social Insurance, Health Insurance (NZOK)
Example: GET /v1/calculate/bg?income=60000

Parameters:
- income (number, required): Gross business income BGN
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- activityType (string): (default: "freelancer") Options: freelancer, sole_trader
- expenses (number): Business expenses BGN (sole_trader only) (default: 0)
- includeOzm (boolean): Include illness & maternity (3.5%) (default: false)
- vatRegistered (boolean): VAT registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### CZ — Czech Republic (Tax Year 2025) | Currency: CZK
Czech OSVČ: Income Tax (15%/23%), Social Insurance, Health Insurance, Flat-Rate Expenses
Example: GET /v1/calculate/cz?income=1000000

Parameters:
- income (number, required): Gross business income CZK
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenseMethod (string): 80% craft, 60% trades (default), 40% professionals, 30% rental, or actual (default: "flat_60") Options: flat_80, flat_60, flat_40, flat_30, actual
- expenses (number): Actual business expenses CZK (expenseMethod=actual only) (default: 0)
- vatRegistered (boolean): DPH registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### RO — Romania (Tax Year 2025) | Currency: RON
Romanian B2B tax calculator: PFA (freelancer, real income) and SRL Micro-Enterprise (1%/3% turnover tax + salary + dividends)
Example: GET /v1/calculate/ro?income=120000&expenses=20000

Parameters:
- income (number, required): Annual gross revenue RON
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- entityType (string): PFA (freelancer) or SRL Micro-Enterprise (default: "pfa") Options: pfa, srl_micro
- expenses (number): Annual business expenses RON (PFA only) (default: 0)
- microRate (number): Micro tax %: 1 (with employee) or 3 (without) (default: 1) Options: 1, 3
- optInCas (boolean): Opt into CAS pension when below threshold (PFA only) (default: false)
- vatRegistered (boolean): TVA registered (19%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 21)

### AE — United Arab Emirates (Tax Year 2025) | Currency: AED
UAE B2B tax calculator: 0% personal income tax for freelancers, 9% corporate tax above AED 375,000 for free zone entities
Example: GET /v1/calculate/ae?income=500000&entityType=freezone&expenses=50000

Parameters:
- income (number, required): Annual gross revenue AED
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- entityType (string): Freelancer (0% tax) or Free Zone entity (9% corp tax) (default: "freelancer") Options: freelancer, freezone
- expenses (number): Annual business expenses AED (freezone only) (default: 0)
- vatRegistered (boolean): VAT registered (5%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 30)

### ME — Montenegro (Tax Year 2025) | Currency: EUR
Montenegrin self-employed tax calculator: Preduzetnik (entrepreneur) with progressive income tax
Example: GET /v1/calculate/me?income=60000&expenses=5000

Parameters:
- income (number, required): Annual gross income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): PDV registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### CY — Cyprus (Tax Year 2025) | Currency: EUR
Cyprus self-employed tax calculator: progressive income tax, social insurance, and GESY (GHS) health contributions
Example: GET /v1/calculate/cy?income=80000&expenses=5000

Parameters:
- income (number, required): Annual gross income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): VAT registered (19%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### SG — Singapore (Tax Year 2025) | Currency: SGD
Singapore self-employed tax calculator: progressive income tax and MediSave contributions
Example: GET /v1/calculate/sg?income=120000&expenses=10000

Parameters:
- income (number, required): Annual gross income in SGD
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- ageGroup (string): Age group for MediSave rate (default: "below35") Options: below35, age35to44, age45to49, age50plus
- vatRegistered (boolean): GST registered (9%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 14)

### HR — Croatia (Tax Year 2025) | Currency: EUR
Croatian self-employed tax calculator: Obrt (real income) and Pausalni Obrt (flat-rate)
Example: GET /v1/calculate/hr?income=60000&expenses=10000&taxModel=obrt

Parameters:
- income (number, required): Gross income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax model (default: "obrt") Options: obrt, pausalni
- expenses (number): Annual deductible expenses (obrt only) (default: 0)
- surtax (string): City surtax (prirez) (default: "zagreb") Options: zagreb, split, rijeka, osijek, none
- vatRegistered (boolean): PDV registered (25%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### HU — Hungary (Tax Year 2025) | Currency: HUF
Hungarian self-employed tax calculator: KATA (fixed tax) and EV (individual entrepreneur)
Example: GET /v1/calculate/hu?income=12000000&taxModel=kata

Parameters:
- income (number, required): Annual gross income in HUF
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax regime (default: "kata") Options: kata, ev
- expenses (number): Annual deductible expenses (EV only) (default: 0)
- vatRegistered (boolean): VAT registered (27%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### TH — Thailand (Tax Year 2025) | Currency: THB
Thai self-employed tax calculator: 8-bracket progressive income tax with expense deduction and personal allowance
Example: GET /v1/calculate/th?income=1200000

Parameters:
- income (number, required): Annual gross income in THB
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- vatRegistered (boolean): VAT registered (7%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 6)

### MY — Malaysia (Tax Year 2025) | Currency: MYR
Malaysian self-employed tax calculator: 10-bracket progressive income tax with personal relief
Example: GET /v1/calculate/my?income=120000

Parameters:
- income (number, required): Annual gross income in MYR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- vatRegistered (boolean): SST registered (8%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 11)

### CR — Costa Rica (Tax Year 2025) | Currency: CRC
Costa Rican self-employed tax calculator: 5-bracket progressive income tax with CCSS social security
Example: GET /v1/calculate/cr?income=24000000

Parameters:
- income (number, required): Annual gross income in CRC
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): IVA registered (13%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

### ID — Indonesia (Tax Year 2025) | Currency: IDR
Indonesian self-employed tax calculator: UMKM simplified (0.5% final) or progressive income tax
Example: GET /v1/calculate/id?income=1000000000&taxModel=umkm

Parameters:
- income (number, required): Annual gross income in IDR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax regime (default: "umkm") Options: umkm, progressive
- vatRegistered (boolean): PPN registered (12%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 12)

### CO — Colombia (Tax Year 2025) | Currency: COP
Colombian self-employed tax calculator: UVT-based progressive income tax with social contributions on IBC
Example: GET /v1/calculate/co?income=100000000

Parameters:
- income (number, required): Annual gross income in COP
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): IVA registered (19%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

### BE — Belgium (Tax Year 2025) | Currency: EUR
Belgian self-employed tax calculator: 4-bracket progressive income tax with tiered social contributions and tax-free allowance
Example: GET /v1/calculate/be?income=80000

Parameters:
- income (number, required): Annual gross income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): BTW registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### FR — France (Tax Year 2025) | Currency: EUR
French micro-entrepreneur tax calculator: Micro-BNC (progressive) or Versement Libératoire (flat)
Example: GET /v1/calculate/fr?income=60000&taxModel=micro_bnc

Parameters:
- income (number, required): Annual turnover in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax regime (default: "micro_bnc") Options: micro_bnc, versement_liberatoire
- vatRegistered (boolean): TVA registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### PH — Philippines (Tax Year 2025) | Currency: PHP
Philippines B2B freelancer tax calculator: 8% flat rate (below PHP 3M) or graduated progressive tax with 3% percentage tax
Example: GET /v1/calculate/ph?income=1500000&taxModel=flat_8

Parameters:
- income (number, required): Annual gross revenue in PHP
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): 8% flat rate (max PHP 3M/yr) or graduated progressive (default: "flat_8") Options: flat_8, graduated
- vatRegistered (boolean): VAT registered (12%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 5)

### IT — Italy (Tax Year 2025) | Currency: EUR
Italian freelancer tax calculator: Forfettario (flat substitute tax 5%/15%) or Ordinario (progressive IRPEF)
Example: GET /v1/calculate/it?income=60000&taxModel=forfettario

Parameters:
- income (number, required): Annual gross revenue in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax regime (default: "forfettario") Options: forfettario, ordinario
- startup (boolean): Startup rate (5% instead of 15%) for forfettario, first 5 years (default: false)
- profitabilityCoefficient (number): Profitability coefficient for forfettario (activity-specific) (default: 0.78)
- vatRegistered (boolean): IVA registered (22%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### LT — Lithuania (Tax Year 2025) | Currency: EUR
Lithuania self-employed individual activity (individuali veikla): progressive income tax 5/15/20%, Sodra social insurance (19.5% on 90% of profit, capped), and fixed PSD health insurance
Example: GET /v1/calculate/lt?income=60000

Parameters:
- income (number, required): Annual gross revenue EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses EUR (default: 0)
- vatRegistered (boolean): VAT registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### GR — Greece (Tax Year 2025) | Currency: EUR
Greece self-employed tax calculator: progressive income tax (9%-44%), EFKA social insurance with reduced rate for new businesses, and optional special regime (50% exemption for relocators)
Example: GET /v1/calculate/gr?income=60000

Parameters:
- income (number, required): Annual gross revenue EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses EUR (reduces taxable base) (default: 0)
- newBusiness (boolean): New business (first 5 years): reduced EFKA rate 146.75/month instead of 220.12/month (default: false)
- specialRegime (boolean): Special tax regime for relocators: 50% income exemption (default: false)
- vatRegistered (boolean): VAT registered (24%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### IE — Ireland (Tax Year 2025) | Currency: EUR
Ireland self-employed tax calculator: progressive income tax (20%/40%) with USC, PRSI, and tax credits
Example: GET /v1/calculate/ie?income=80000

Parameters:
- income (number, required): Annual gross revenue EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses EUR (default: 0)
- vatRegistered (boolean): VAT registered (23%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### AT — Austria (Tax Year 2025) | Currency: EUR
Austria self-employed (Einzelunternehmer) tax calculator: progressive income tax up to 55%, SVS social insurance (26.83% + accident), Gewinnfreibetrag deduction up to 4,950 EUR
Example: GET /v1/calculate/at?income=80000&expenses=10000

Parameters:
- income (number, required): Annual gross revenue EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses EUR (default: 0)
- vatRegistered (boolean): VAT registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### SE — Sweden (Tax Year 2025) | Currency: SEK
Sweden Enskild Firma (sole trader) tax calculator: egenavgifter (28.97%), municipal income tax (~32.37%), state tax (20% above SEK 613,900)
Example: GET /v1/calculate/se?income=600000&expenses=0

Parameters:
- income (number, required): Annual gross revenue SEK
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses SEK (default: 0)
- municipalRate (number): Municipal tax rate (varies by municipality, national average 0.3237) (default: 0.3237)
- vatRegistered (boolean): VAT registered (25%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### IL — Israel (Tax Year 2025) | Currency: ILS
Israel self-employed (עצמאי) tax calculator: progressive income tax with credit points, National Insurance (Bituach Leumi), and health tax
Example: GET /v1/calculate/il?income=300000

Parameters:
- income (number, required): Annual gross revenue ILS
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses ILS (default: 0)
- vatRegistered (boolean): VAT registered (18%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 12)

### IN — India (Tax Year 2025) | Currency: INR
India B2B freelancer tax calculator: presumptive taxation (44ADA, 50% deemed income), new regime (progressive with standard deduction + rebate), or old regime (legacy brackets). Health & education cess 4% applies.
Example: GET /v1/calculate/in?income=3000000&taxModel=presumptive

Parameters:
- income (number, required): Annual gross revenue INR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): presumptive: 44ADA (50% deemed), new_regime: progressive with deduction, old_regime: legacy brackets (default: "presumptive") Options: presumptive, new_regime, old_regime
- vatRegistered (boolean): GST registered (18%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

### DK — Denmark (Tax Year 2025) | Currency: DKK
Danish self-employed (selvstændig) tax calculator with AM-bidrag, bundskat, kommuneskat, optional kirkeskat, topskat, and tax ceiling
Example: GET /v1/calculate/dk?income=600000

Parameters:
- income (number, required): Annual income in DKK
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- municipalRate (number): Municipal tax rate (national average 25.1%) (default: 0.251)
- churchTax (boolean): Whether church tax applies (default: false)
- churchRate (number): Church tax rate (average 0.7%) (default: 0.007)
- vatRegistered (boolean): VAT registered (25% moms) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### FI — Finland (Tax Year 2025) | Currency: EUR
Finnish self-employed tax calculator with YEL pension and progressive state+municipal tax
Example: GET /v1/calculate/fi?income=60000

Parameters:
- income (number, required): Annual income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual business expenses in EUR (default: 0)
- municipalRate (number): Municipal tax rate (national average 9.28%) (default: 0.0928)
- vatRegistered (boolean): VAT registered (25.5%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### NO — Norway (Tax Year 2025) | Currency: NOK
Norwegian self-employed (Enkeltpersonforetak) tax calculator: Trinnskatt, ordinary tax, and trygdeavgift
Example: GET /v1/calculate/no?income=700000

Parameters:
- income (number, required): Gross income NOK
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible expenses (default: 0)
- vatRegistered (boolean): MVA registered (25%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### CH — Switzerland (Tax Year 2025) | Currency: CHF
Swiss self-employed (Selbstständig) tax calculator with federal progressive tax, cantonal tax, and AHV/IV/EO social insurance
Example: GET /v1/calculate/ch?income=120000

Parameters:
- income (number, required): Annual gross income in CHF
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses (default: 0)
- cantonalRate (number): Effective cantonal/municipal tax rate (0-1). Default 0.12 approximates Zurich (default: 0.12)
- vatRegistered (boolean): MWST registered (8.1%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 25)

### LV — Latvia (Tax Year 2025) | Currency: EUR
Latvian self-employed tax calculator: Standard (progressive PIT + SSC) or Micro-enterprise (flat 25%)
Example: GET /v1/calculate/lv?income=40000&taxModel=standard

Parameters:
- income (number, required): Annual income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax regime (default: "standard") Options: standard, micro
- expenses (number): Business expenses (standard model only) (default: 0)
- vatRegistered (boolean): VAT registered (21%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### SK — Slovakia (Tax Year 2025) | Currency: EUR
Slovak SZČO: Income Tax (15%/19%/25%), Social Insurance, Health Insurance, Flat-Rate Expenses
Example: GET /v1/calculate/sk?income=60000

Parameters:
- income (number, required): Gross business income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- useFlatExpenses (boolean): Use 60% flat expense deduction (max 20,000 EUR) (default: true)
- actualExpenses (number): Actual business expenses EUR (useFlatExpenses=false only) (default: 0)
- vatRegistered (boolean): DPH registered (23%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### SI — Slovenia (Tax Year 2025) | Currency: EUR
Slovenian self-employed tax calculator: Normiranec (flat-rate 80% normative) and Standard (progressive)
Example: GET /v1/calculate/si?income=80000

Parameters:
- income (number, required): Annual gross income in EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxModel (string): Tax model (default: "normiranec") Options: normiranec, standard
- expenses (number): Annual deductible expenses (standard model only) (default: 0)
- vatRegistered (boolean): DDV registered (22%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 20)

### MT — Malta (Tax Year 2025) | Currency: EUR
Maltese self-employed tax calculator: Progressive income tax (single rates) and Class 2 SSC
Example: GET /v1/calculate/mt?income=50000

Parameters:
- income (number, required): Gross business income EUR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses (default: 0)
- vatRegistered (boolean): VAT registered (18%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 24)

### TR — Turkey (Tax Year 2025) | Currency: TRY
Turkish self-employed (serbest meslek) tax calculator with BAG-KUR social security
Example: GET /v1/calculate/tr?income=500000

Parameters:
- income (number, required): Gross income in TRY
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- expenses (number): Annual deductible business expenses (default: 0)
- bagkurBase (string): BAG-KUR contribution base selection (default: "minimum") Options: minimum, actual, maximum
- vatRegistered (boolean): KDV registered (20%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 14)

### UA — Ukraine (Tax Year 2025) | Currency: UAH
Ukrainian ФОП (FOP): Unified Tax, Military Levy, ESV Social Contribution
Example: GET /v1/calculate/ua?income=1000000

Parameters:
- income (number, required): Gross business income UAH
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- fopGroup (string): FOP group (group3 = 5% flat, most common for IT) (default: "group3") Options: group2, group3
- vatPayer (boolean): VAT payer (20%). Group 3 with VAT pays 3% unified tax instead of 5% (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 24)

### BR — Brazil (Tax Year 2025) | Currency: BRL
Brazilian Tax: MEI (fixed DAS), Simples Nacional (tiered), or Autônomo (progressive IRPF + INSS)
Example: GET /v1/calculate/br?income=60000&taxRegime=mei

Parameters:
- income (number, required): Gross business income BRL
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxRegime (string): MEI = fixed low tax (up to R$81k), Simples = tiered, Autônomo = progressive (default: "mei") Options: mei, simples, autonomo
- activityType (string): Affects ISS/ICMS in MEI regime (default: "services") Options: services, commerce
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (Brazil standard: 30) (default: 30)

### VN — Vietnam (Tax Year 2025) | Currency: VND
Vietnamese PIT: Progressive brackets or simplified business tax, social/health/unemployment insurance
Example: GET /v1/calculate/vn?income=500000000&taxMethod=simplified

Parameters:
- income (number, required): Gross income VND
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- taxMethod (string): Progressive PIT (7 brackets 5-35%) or simplified business tax (5% services) (default: "simplified") Options: progressive, simplified
- dependents (number): Number of dependents (4.4M VND deduction each) (default: 0)
- vatRegistered (boolean): VAT registered (8%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 12)

### ZA — South Africa (Tax Year 2025) | Currency: ZAR
South African Tax: Progressive income tax with rebates, UIF
Example: GET /v1/calculate/za?income=500000

Parameters:
- income (number, required): Gross income ZAR
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- age (number): Age (affects tax rebates: primary, 65+, 75+) (default: 30)
- vatRegistered (boolean): VAT registered (15.5%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 21)

### KR — South Korea (Tax Year 2025) | Currency: KRW
South Korean Tax: Progressive income tax (6-45%) + 10% local surtax, NPS, NHI, Long-term Care
Example: GET /v1/calculate/kr?income=60000000

Parameters:
- income (number, required): Gross income KRW
- incomePeriod (string): (default: "yearly") Options: monthly, yearly
- includeNps (boolean): Include National Pension (9% of income, capped) (default: true)
- includeEi (boolean): Include Employment Insurance (2.25%, optional for self-employed) (default: false)
- vatRegistered (boolean): VAT registered (10%) (default: false)
- weeklyHours (number): Weekly working hours (default: 40)
- paidDaysOff (number): Annual leave days (default: 15)

---

## Response Format

All /v1/calculate/:country endpoints return:

```json
{
  "country": "de",
  "currency": "EUR",
  "taxYear": 2025,
  "input": { },
  "monthly": {
    "gross": 5000.00,
    "vat": 0,
    "grossWithVat": 5000.00,
    "socialInsurance": 846.89,
    "healthInsurance": 0,
    "incomeTax": 671.83,
    "totalDeductions": 1518.72,
    "net": 3481.28
  },
  "yearly": {
    "gross": 60000.00,
    "socialInsurance": 10162.68,
    "healthInsurance": 0,
    "incomeTax": 8061.92,
    "totalDeductions": 18224.60,
    "net": 41775.40
  },
  "rates": {
    "effectiveTaxRate": 0.3037,
    "dailyRate": 189.03,
    "hourlyRate": 23.63,
    "workingDays": 221
  },
  "details": { }
}
```

Key fields:
- yearly.net — Annual take-home pay
- monthly.net — Monthly take-home pay
- rates.effectiveTaxRate — Total tax burden as decimal (0-1)
- rates.hourlyRate — Effective hourly rate after all deductions
- rates.dailyRate — Net income per working day
- details — Country-specific breakdown (brackets, bases, intermediate values)

Errors: HTTP 400/404 with { "error", "code", "hint", "docs" }

## Notes

- No authentication required
- CORS enabled for all origins
- No rate limits
- All countries support incomePeriod (monthly/yearly). Poland defaults to monthly; most others default to yearly
- Income is in local currency unless the country supports currency selection (Serbia: EUR or RSD)
- Source: rel.tax