Gross salary before tax from PAYE employment
Net profit from self-employment after expenses
Personal pension contributions (gross amount)
Donations made under Gift Aid (amount you paid)
Reg. 07380272 · England & Wales · Est. 2010
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Total Tax Bill
£8,205.60
Tax Owed (After PAYE)
£3,325.20
Effective Rate
18.2%
Net Income
£36,794.40
Everything you need to know about Self-Assessment tax in the UK
Who needs to file a Self-Assessment tax return?
You must file a Self-Assessment tax return if you are self-employed and earned more than £1,000, a company director, have annual income over £150,000, receive income from property lettings, have savings or investment income over certain thresholds, earn untaxed income, have capital gains to report, or need to claim tax relief. You must register with HMRC by 5 October following the end of the tax year in which you first need to file.
What are the Self-Assessment deadlines?
For the 2025/26 tax year (6 April 2025 to 5 April 2026), the key deadlines are: 5 October 2026 to register if you are new, 31 October 2026 for paper tax returns, 31 January 2027 for online tax returns and payment of any tax owed, and 31 July 2027 for the second payment on account. Late filing incurs an automatic £100 penalty, rising to £10 per day after 3 months.
What are payments on account?
Payments on account are advance payments towards your next year's tax bill. HMRC requires them when your Self-Assessment tax liability exceeds £1,000 and less than 80% of your tax is collected at source through PAYE. Each payment on account is 50% of the previous year's Self-Assessment liability. The first is due on 31 January (alongside your balancing payment for the current year) and the second on 31 July.
How is tax calculated on multiple income sources?
All your non-dividend income (employment, self-employment, rental, and savings) is added together to determine your total taxable income. Your Personal Allowance (£12,570) is deducted, and income tax is charged on the remainder at the appropriate rates (20% basic, 40% higher, 45% additional). Dividend income is taxed separately at its own rates (8.75%, 33.75%, 39.35%) after a £500 tax-free dividend allowance.
HMRC-Aligned: This estimator uses official 2025/26 tax rates, NI thresholds, and payment on account rules. Results are estimates only and do not constitute tax advice. Consult HMRC or a qualified accountant for your actual Self-Assessment filing.
This calculator uses official rates and thresholds from:
Last verified: February 2026 · Tax year 2025/26. Results are indicative — consult a qualified accountant for personalised advice.
Reviewed by M. Samiuddin Quadri, ACCA — Chartered Certified Accountant at Gladstone & Co. · Updated for the 2025/26 tax year.
Disclaimer: This calculator provides estimates based on current HMRC rates and thresholds for the 2025/26 tax year. It does not constitute professional tax, financial, or legal advice. Your actual liability may differ depending on your individual circumstances. Always consult a qualified accountant or tax adviser before making financial decisions. Read our terms