Self Assessment Calculator
Estimate your self-employment tax bill for 2025/26
Last updated: April 2025 · 2025/26 tax rates
Self-Employed Income
£
Total business income
£
Business costs you can deduct
Taxable Profit£40,000
Other Income
£
Employment, rental, etc.
£
From shares or company
Deductions
£
Personal pension payments
£
Charitable donations
Scottish taxpayer?
Different income tax bands
Total Tax Bill 2025/26
£8,134
Income Tax + National Insurance
Effective Rate
20.3%
Total Income
£40,000
Income Tax
£5,486
National Insurance
£2,648
Net Income
£31,866
Tax Breakdown
Self-Employed Profit£40,000
Total Income£40,000
Personal Allowance-£12,570
Income Tax Calculation
Basic Rate (20%)£27,430
Tax:£5,486
Total Income Tax£5,486
National Insurance Calculation
Class 2 NI£3.45/week × 52
Annual:£179
Class 4 NIOn profit over £12,570
£12,570 - £50,270 at 9%:£2,469
Total Class 4:£2,469
Total National Insurance£2,648
Payment Schedule
You pay your tax bill in three installments: a balancing payment plus two payments on account for next year.
31 January 2025
Balancing payment + 1st payment on account
£12,201
• Balancing payment: £8,134
• 1st payment on account: £4,067
31 July 2025
2nd payment on account
£4,067
Total to pay in 12 months: £16,268
Self Assessment Guide
You Must File Self Assessment If You:
- • Are self-employed (sole trader or partnership)
- • Have untaxed income over £1,000 (excluding employment)
- • Are a company director (unless PAYE covers all tax)
- • Have income over £100,000
- • Receive income from abroad
- • Rental income over £2,500 (or £1,000 with expenses)
- • Capital gains above the annual allowance
- • Want to claim certain tax reliefs
Tax year 2025/26 (6 April 2025 - 5 April 2026) | Rates and allowances subject to change