NorTax-TS

A TypeScript client for the Norwegian tax authority’s API, based on the original Python package. This library focuses on fetching Norwegian tax calculations for various income types, periods, and tables.

Note: This library is the TypeScript variant of the Nortax project. For the Python version, visit github.com/lewiuberg/nortax.

Table of Contents

• Installation
• Usage
  • Import the Tax Class
  • Create a Tax Object
  • Obtain Tax Details
  • Retrieving the Whole Table
• Examples
• Testing
• Supported Values
  • Income Types
  • Periods
  • Tax Tables
• License

Installation

npm install nortax-ts

Or use your preferred package manager:

yarn add nortax-ts
pnpm add nortax-ts

Usage

Import the Tax Class

import { Tax } from 'nortax-ts';

Create a Tax Object

// Create a Tax object with default or custom parameters
const tax = new Tax(
25000,        // grossIncome
'7100',       // taxTable
'Pension',    // incomeType
'2 weeks',    // period
2024          // year
);

Obtain Tax Details

(async () => {
// Get the deduction
const deduction = await tax.getDeduction();
console.log('Tax deduction:', deduction);

// Get the net income
const netIncome = await tax.getNetIncome();
console.log('Net income:', netIncome);

// Get a descriptive string with all details
const fullDetails = await tax.getFullDetails();
console.log(fullDetails);
})();

Example output (for getFullDetails()):

URL: str = https://api-tabellkort.app.skatteetaten.no/?valgtTabell=7100&valgtInntektType=Pensjon&valgtPeriode=PERIODE_14_DAGER&valgtLonn=25000&visHeleTabellen=false&valgtAar=2024&hentHeleTabellen=false
Tax table: valid_tables = 7100
Income type: income_type = Pension
Period: period = 2 weeks
Year: int = 2024
Gross income: int = 25000
Tax deduction: int = 6735
Net income: int = 18265

Retrieving the Whole Table

(async () => {
const wholeTable = await tax.getWholeTable();
console.log('Whole table:', wholeTable);
})();

Example output (truncated for readability):

{
"30000": 6971,
"40000": 10872,
"50000": 14774
}

Examples

import { Tax } from 'nortax-ts';

(async () => {
// 1) Instantiate a Tax object with desired parameters
const myTax = new Tax(50000, '7100', 'Wage', 'Monthly', 2024);

// 2) Fetch deduction
const deduction = await myTax.getDeduction();
console.log(`Monthly deduction on 50k gross: ${deduction}`);

// 3) Fetch net income
const netIncome = await myTax.getNetIncome();
console.log(`Net income: ${netIncome}`);

// 4) Obtain the entire deduction table if needed
const table = await myTax.getWholeTable();
console.log('Deduction table for various incomes:', table);
})();

Testing

This project uses Jest for both unit and integration testing.

• Run all tests (without integration tests):

  npm test

• Run with coverage:

  npm run test:coverage

• Run integration tests (this hits the live API; ensure your network is available):

  npm run test:integration

Supported Values

Income Types

• Wage
• Pension

Periods

• 1 day
• 2 days
• 3 days
• 4 days
• 1 week
• 2 weeks
• Monthly

Tax Tables

The tax tables are year-specific in the Norwegian tax system:

2020-2024 Tables

Standard tables (7100-7133), special tables (7150, 7160, 7170), and pension tables (6300, 6350, etc.).

Example usage:

// Valid for 2020-2024
const tax2024 = new Tax(50000, '7100', 'Wage', 'Monthly', 2024);

2025 Tables

New table system starting with 8xxx series (8100-8133, 8150, 8160, etc.).

Example usage:

// Valid only for 2025
const tax2025 = new Tax(50000, '8150', 'Wage', 'Monthly', 2025);

Note: Using a tax table with an incorrect year (e.g., trying to use table '8150' in 2024) will throw an error.

Error handling example:

// This will throw an error
try {
  const invalidTax = new Tax(50000, '8150', 'Wage', 'Monthly', 2024);
} catch (error) {
  console.error(error); // Error: Invalid tax table "8150" for year 2024
}

For a complete list of valid tables per year, see:

• 2020-2024 Tables
• 2025 Tables

License

This project is released under the MIT License.

For more details on the original Python package, visit github.com/lewiuberg/nortax.