UK Tax & NI Calculator

Web app and API for UK PAYE-style tax and National Insurance calculations.

Live demo: https://tax.log7.uk/calculator/

Current State

• HMRC-oriented pipeline is the default and only calculation mode in UI/API.
• Supports Scotland/rUK behavior via flags and tax-code prefixes (S/C).
• API is protected with JWT bearer token.
• Tax rates are stored in DB and synced from seed data.

Quick Start (Local)

python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python manage.py migrate
python manage.py sync_tax_rates
python manage.py runserver

Open:

• http://127.0.0.1:8000/calculator/

API Authentication

Get JWT token:

curl -X POST http://127.0.0.1:8000/calculator/api/token/ \
  -H "Content-Type: application/json" \
  -d '{"username":"YOUR_USER","password":"YOUR_PASSWORD"}'

Use token:

curl -X POST http://127.0.0.1:8000/calculator/api/calculate/ \
  -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
        "tax_year": 2025,
        "income": 60000,
        "income_type": "yearly",
        "workweek_hours": 40,
        "tax_code": "1257L",
        "is_blind": false,
        "no_ni": false,
        "mca": false,
        "is_scotland": false
      }'

CI/CD & Deployment

• Source code is published via GitHub.
• On push to master, GitHub Actions runs the deployment workflow.
• The app is deployed to Azure Web App (tax-calculator).
• Startup bootstrap is automated on Azure (startup.sh) to run migrations and rate sync.

This part of the project is also used as a practical DevOps skills showcase (CI/CD pipeline setup, secure deployment flow, and environment-based runtime configuration).

Azure Web App demo: https://tax-calculator-abhnf5crftcxg4fu.eastus-01.azurewebsites.net/calculator/

Notes

• This is not an official HMRC service.
• Use results for demonstration/planning, not as legal tax advice.