Finance⏱ 7 min read
10 Legal Ways to Reduce Your UK Tax Bill
Most people pay more tax than they need to simply because they don't know which reliefs and allowances apply to them. Here are the most impactful, widely-applicable ones for 2024/25.
Tax avoidance (using legal means to reduce your bill) is explicitly encouraged by HMRC through allowances and reliefs built into the tax code. Tax evasion (illegal non-payment) is criminal. Everything below is firmly in the former category.
1. Maximise Your ISA Allowance
Annual ISA allowance: £20,000 per person
A couple: £40,000 per year sheltered
Tax saved (higher-rate taxpayer with large portfolio):
£50,000 in dividends inside ISA vs outside:
Outside: dividend tax at 33.75% = £16,875/year
Inside ISA: £0
10-year saving: £168,750+
2. Pension Contributions (20–45% Tax Relief)
Contributing to a pension is the only way to get money into an investment
completely free of income tax.
Higher-rate taxpayer contributes £8,000 net:
Government adds 40% relief: £12,000 invested in pension
Immediate 50% uplift on your money
Additional-rate taxpayer: effective uplift of 82% (putting in £5,500 creates £10,000 in pension)
3. Use the Marriage Allowance
If one spouse is a non-taxpayer (income below £12,570)
and the other is a basic-rate taxpayer:
Non-taxpayer can transfer £1,260 of personal allowance to partner
Tax saving: £1,260 × 20% = £252/year
Can be backdated up to 4 years if not previously claimed
= up to £1,008 in backdated refunds
4. Transfer Assets to Lower-Earning Spouse
Income from jointly-held savings or investments is split 50/50 by default for tax purposes. But you can transfer assets to the spouse with the lower (or zero) tax rate. Savings interest taxed at the basic rate (20%) vs the higher rate (40%) on the same £50,000 of savings generates a £500/year difference in tax paid.
5. Use the £1,000 Trading Allowance
You can earn up to £1,000/year from self-employment
or casual income completely tax-free (no need to register or report).
Examples: selling crafts, occasional odd jobs, car boot sales.
Above £1,000: must register with HMRC as self-employed.
6. Use Capital Gains Tax Annual Exemption
CGT Annual Exempt Amount (2024/25): £3,000
Gains up to £3,000/year are completely CGT-free.
A couple: £6,000 in gains tax-free per year.
Strategy: crystallise gains up to the exemption each year
("bed and ISA" — sell and rebuy inside ISA wrapper).
This resets your cost basis and avoids future CGT on the same gains.
7. Claim All Allowable Business Expenses
If self-employed, expenses wholly and exclusively for business purposes are deductible from taxable profit. Commonly missed: home office (£6/week flat rate or proportion of bills), mobile phone (business %) subscriptions, professional development, equipment.
Additional £3,000 of unclaimed expenses for 20% taxpayer:
= £600 in tax saved + £218 NI saved = £818/year
8. Gift Aid on Charitable Donations
Basic-rate taxpayer donates £800 to charity:
Gift Aid allows charity to reclaim 25p per £1: charity receives £1,000
Higher-rate taxpayer: claim the extra 20% difference via Self Assessment
= £200 personal tax refund on the same donation
9. EIS/SEIS for Higher-Risk Investing
Enterprise Investment Scheme (EIS) and Seed EIS offer 30–50% income tax relief on investments in qualifying small companies, plus CGT deferral and loss relief. High risk — only for those who understand the investments. But the tax treatment makes even risky bets more viable for higher earners.
10. Make Sure You're on the Right Tax Code
HMRC frequently issues incorrect tax codes, particularly after job changes, starting or stopping benefits-in-kind, or starting to draw a pension. Check your tax code on your payslip (it should start with a number near 1257 for standard personal allowance). An incorrect code can mean overpaying hundreds of pounds per year — and you can reclaim for up to four previous tax years.