UK NI & Employer Tax Calculator (2025-2026)

A WordPress plugin for calculating UK Income Tax, National Insurance, and Employer NI contributions for the 2025-2026 tax year.

Features

• ✅ Accurate Calculations - Based on official HMRC rates for 2025-2026
• 📊 Complete Breakdown - Income Tax, Employee NI, Employer NI, and net income
• 📅 Annual & Monthly Figures - View both timeframes
• 📈 Percentage Display - See what percentage goes to each tax
• 🎨 Responsive Design - Works on desktop, tablet, and mobile
• ⚡ Easy Integration - Simple shortcode [uk_tax_calculator]
• 🎯 No Configuration - Works out of the box
• 🔒 Privacy-Focused - No data collection or external API calls

Installation

From WordPress Admin

1. Download the latest release
2. Go to Plugins > Add New > Upload Plugin
3. Choose the ZIP file and click Install Now
4. Activate the plugin
5. Add [uk_tax_calculator] to any page or post

Manual Installation

1. Clone this repository or download the ZIP
2. Upload to /wp-content/plugins/
3. Activate through the WordPress admin panel
4. Add [uk_tax_calculator] to any page or post

Usage

Simply add the shortcode to any page, post, or widget:

[uk_tax_calculator]

Users can then:

1. Enter their gross annual salary
2. Enter their tax code (optional, defaults to 1257L)
3. Click "Calculate Tax"
4. View the complete breakdown

Tax Rates (2025-2026)

Income Tax (PAYE)

• Personal Allowance: £12,570
• Basic Rate (20%): £12,571 to £50,270
• Higher Rate (40%): £50,271 to £125,140
• Additional Rate (45%): Over £125,140

Employee National Insurance (Category A)

• Primary Threshold: £12,570
• 8% on earnings between £12,570 and £50,270
• 2% on earnings above £50,270

Employer National Insurance

• Secondary Threshold: £5,000
• 15% on all earnings above £5,000

Example Calculation

For a salary of £50,000:

Employer Costs: | Item | Annual | Monthly | |------|--------|---------| | Salary | £50,000 | £4,167 | | Employer's NI | £6,750 | £563 | | TOTAL COST | £56,750 | £4,729 |

Customization

Custom CSS

You can customize the appearance by adding CSS to your theme:

.uk-tax-calculator-container {
    /* Your custom styles */
}

Integration with Page Builders

The calculator works with all major page builders:

• Elementor
• Beaver Builder
• Divi Builder
• WPBakery
• Gutenberg

Just add the shortcode in a shortcode widget or module.

Technical Details

File Structure

uk-tax-calculator/
├── assets/
│   ├── css/
│   │   └── calculator.css
│   └── js/
│       └── calculator.js
├── templates/
│   └── calculator-form.php
├── uk-tax-calculator.php
├── readme.txt
└── README.md

Browser Support

• Chrome (latest)
• Firefox (latest)
• Safari (latest)
• Edge (latest)
• Mobile browsers

Security Features

• WordPress nonce verification
• Input sanitization
• AJAX request validation
• No external API calls
• No data storage

Development

Requirements

• WordPress 5.0 or higher
• PHP 7.0 or higher
• jQuery (included with WordPress)

Local Development

1. Clone the repository
2. Copy to your WordPress wp-content/plugins/ directory
3. Activate the plugin
4. Start developing!

Support

For issues, questions, or contributions:

• Open an issue on GitHub
• Submit a pull request
• Check the WordPress.org support forum

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Open a pull request

Legal Disclaimer

This calculator provides estimates based on standard UK tax rates for the 2025-2026 tax year. Actual tax liability may vary depending on individual circumstances. Always verify calculations with HMRC or consult a qualified tax professional.

Credits

Tax rates and thresholds based on official HMRC guidance for the 2025-2026 tax year.

License

This project is licensed under the GPL v2 or later - see the LICENSE file for details.

Changelog

Version 1.0.0

• Initial release
• Income Tax (PAYE) calculation
• Employee National Insurance calculation
• Employer National Insurance calculation
• Support for custom tax codes
• Responsive design
• Annual and monthly breakdowns

Author

Faruk Desk

• GitHub: @farukdesk

Made with ❤️ for the WordPress community