UK Car Capital Allowances Calculator

🚗 Core Functionality

  • HMRC-compliant calculations based on official UK tax rules
  • Calculates allowable capital allowances for business cars
  • Uses current rates and thresholds for 2025/26 tax year
  • Automatic rate determination based on CO₂ emissions

 

📊 Capital Allowance Rates

  • 100% First Year Allowance: for new, unused electric or zero-emission cars
  • Main Rate (18%): for cars with CO₂ ≤ 50g/km
  • Special Rate (6%): for cars with CO₂ > 50g/km
  • Exclusions warning: No AIA, Super-deduction, or Full Expensing
  • Visual indicators for allowances and exclusions

 

💰 Input Fields

  • Purchase Price (£): Enter total cost with currency formatting
  • CO₂ Emissions (g/km): Link to GOV.UK for emissions data
  • Purchase Date Period: Dropdown for current and historical rules
  • Car Condition: Dropdown for "New" or "Second-hand"
  • Business Use Percentage: 0-100% input for pro-rata calculation
  • Business Type: Select "Sole Trader" or "Limited Company"
  • Tax Rate (Optional): Input with guidance for tax savings estimate

 

🧮 Calculation Features

  • "Calculate Capital Allowances" button processes all inputs
  • Automatic rate selection based on CO₂ emissions and purchase date
  • Adjusts allowance based on business use percentage
  • Estimates tax savings when tax rate is provided
  • Instant display of results with smart logic for rate application

⚖️ HMRC Compliance

  • Based on official UK capital allowances rules and legislation
  • Professional disclaimer: "Always consult with a qualified accountant"
  • Notice: "Tax year 2025/26 rates apply. Rules may change"
  • Follows accurate emission thresholds for rate determination

📱 User Interface

  • Clean, professional design with an easy-to-navigate layout
  • Informative key information box at the top
  • Light/dark mode toggle for user preference
  • Responsive form layout with organized input sections
  • Clear field labels and helpful placeholder text

🎓 Educational Features

  • Built-in guidance explaining each allowance type
  • GOV.UK integration linking to official emissions data
  • Examples for different tax rates and business types
  • Visual indicators (color-coded checkmarks, warnings)
  • Inline help text for contextual assistance

 

📈 Tax Planning Support

  • Allows comparison of different vehicle scenarios
  • Helps optimize business use percentage impact
  • Provides visibility into actual tax benefits and savings
  • Supports both sole traders and limited companies
  • Uses current legislation and precise thresholds for accuracy

 

This calculator is essential for UK business owners, accountants, and tax advisors to accurately determine capital allowances for business vehicles and optimize tax relief based on vehicle emissions and usage.