🇬🇧 United Kingdom tax & finance calculators

UK tax planning: PAYE, Self Assessment, ISAs and pensions

The UK tax system covers Income Tax, National Insurance (NI), Capital Gains Tax (CGT), Inheritance Tax (IHT), and a range of allowances and reliefs. Most employees never file a tax return because PAYE handles withholding automatically. Self-employed, landlords, high-earners (above 100K), and people with significant investment income must file Self Assessment by 31 January following the tax year.

2025/26 Income Tax bands (England, Wales, Northern Ireland)

Above 100,000 GBP, the personal allowance tapers away by 1 GBP for every 2 GBP of income, creating an effective marginal rate of 60% in the 100K-125,140 band. This is the famous UK "60% tax trap" - a common reason high earners use salary sacrifice or pension contributions to push reported income below 100K.

National Insurance contributions

Employees pay Class 1 NI: 8% on weekly earnings between 242 GBP and 967 GBP, plus 2% above 967 GBP. Employers pay 13.8%. Self-employed pay Class 4: 6% between 12,570 and 50,270 plus 2% above. NI funds the State Pension and contributory benefits.

Top tax-efficient wrappers

• ISA (Individual Savings Account): 20,000 GBP per year. Cash, Stocks and Shares, or Innovative Finance flavors. All gains, dividends, and interest tax-free forever. No limit on accumulated balance.
• Lifetime ISA (LISA): 4,000 GBP/year (counts toward 20K). Government adds 25% bonus. Use for first home (up to 450K) or retirement at 60. 25% withdrawal penalty otherwise.
• SIPP (Self-Invested Personal Pension): 60,000 GBP annual allowance. Tax relief at marginal rate (20/40/45%). 25% tax-free lump sum at 55+ (rising to 57 in 2028). Lifetime Allowance abolished 2024.
• Workplace pension: 8% minimum (3% employer, 5% employee) under auto-enrolment. Many employers match more.
• Capital Gains Tax annual exempt amount: 3,000 GBP for 2025/26 (down from 6K in 2023/24, 12,300 in 2022/23). Above that, 18% basic rate / 24% higher rate on residential property; 18% / 24% on shares (raised from 10/20% in October 2024 Budget).

Scottish income tax (different bands)

Scottish residents pay different rates: 19% starter, 20% basic, 21% intermediate, 42% higher, 45% advanced, 48% top. Scotland also has a tighter personal allowance taper. Northern Ireland and Wales use rUK rates.

Common UK tax planning strategies

1. Pension salary sacrifice: avoids both income tax AND National Insurance. A 100 GBP salary sacrifice into pension nets ~108 GBP of pension contribution (employer NI saved often shared).
2. Marriage Allowance: lower-earning spouse transfers 1,260 GBP of personal allowance to higher earner. Saves up to 252 GBP/year. Eligible if higher earner is basic-rate (not higher-rate).
3. Spouse income splitting: assets in lower-earner's name pay less tax on dividends/interest. Especially powerful for buy-to-let and dividend-paying investments.
4. Bed and ISA: sell investments in your General Investment Account, immediately repurchase same in your ISA. Crystallises gains within annual exemption, then shelters future growth.
5. EIS/SEIS investing: 30%/50% income tax relief on qualifying startup investments, plus CGT relief and IHT exemption after 2 years.

Calculators by UK nation

Localized 2026 tax math + keyword-targeted pages for every UK region. Each links to: Salary Calculator, Income Tax, Stamp Duty.