How to Legally Reduce Your Tax Bill in the UK
Ten HMRC-approved methods to pay less tax in 2025-26. No complicated schemes — just straightforward reliefs that millions of people miss every year.
1. Salary Sacrifice Into Pension
The single most effective method for most employees. Under salary sacrifice, your employer reduces your gross salary by the pension contribution amount before tax and National Insurance are calculated. On £50,000 salary, sacrificing £5,000 saves approximately:
- Income tax: £5,000 × 40% (higher rate) = £2,000 saved
- NI: £5,000 × 2% (above £50,270) = £100 saved
- Total saving: ~£2,100 per year
On a basic rate salary of £30,000, sacrificing £2,000: income tax saved = £400, NI saved = £160, total = £560 per year. Employers often share their NI saving too (13.8%), making some salary sacrifice schemes even more valuable.
2. Maximise Your ISA Allowance
The annual ISA limit is £20,000 per person in 2025-26. All investment growth, dividends, and interest inside an ISA are permanently tax-free. For a higher rate taxpayer holding dividend-paying shares outside an ISA, moving them inside the wrapper could save 33.75% dividend tax per year on income above the £500 allowance. ISAs have no minimum holding period and no tax on withdrawal.
3. Claim Marriage Allowance
If you are married or in a civil partnership and one partner earns below £12,570 while the other earns £12,571–£50,270, claim Marriage Allowance. The lower earner transfers £1,260 of their Personal Allowance, saving the couple £252 per year. You can backdate up to four years for a lump-sum refund of up to £1,008. Apply at gov.uk/marriage-allowance — takes five minutes.
4. Claim Work-Related Expenses
HMRC allows deductions for genuine work expenses not reimbursed by your employer:
- Uniforms and specialist clothing: HMRC flat rates by industry (e.g., £185/year for healthcare workers)
- Professional subscriptions: GMC, NMC, Law Society, CIPD, RICS — claim the full amount paid
- Tools and equipment: if you must buy your own and are not reimbursed
- Working from home allowance: £6/week (£312/year) without receipts if your employer has not paid it
A basic rate taxpayer claiming £500 of work expenses saves £100 in income tax and £40 in NI — and you can backdate four years via a P87 form.
5. Use the Trading Allowance
If you earn income from a side hustle, selling items, or casual work, the first £1,000 per year is completely tax-free under the trading allowance. You do not need to register for Self Assessment or report it to HMRC if your total trading income is below £1,000. A basic rate taxpayer saves up to £200 in tax; a higher rate taxpayer saves up to £400.
6. Use the Property Allowance
Similarly, the first £1,000 of rental income per year is tax-free under the property allowance. If you rent a room occasionally (e.g., on Airbnb for a weekend), income below £1,000 requires no reporting. Above £1,000 consider the Rent a Room Scheme (£7,500/year tax-free threshold) if letting a room in your own home.
7. Gift Aid: Higher Rate Taxpayers Get Extra Relief
When you donate to a registered charity and tick the Gift Aid box, the charity claims 25% on top of your donation (from HMRC). As a higher rate taxpayer, you can also claim the difference between higher rate (40%) and basic rate (20%) through Self Assessment. On a £100 donation: charity receives £125; you claim 20% of £125 = £25 back. Effectively, a £100 donation to charity costs you only £75.
8. Cycle to Work Scheme
Employers can provide bikes and cycling equipment via salary sacrifice, spreading the cost over 12 months from your gross pay. Because payments reduce your taxable salary, you save income tax and NI on every pound. A basic rate taxpayer buying a £1,000 bike pays effectively £720 after tax and NI savings (28% saving). No CO2 emissions BIK — the equipment is completely exempt from Benefit in Kind tax.
9. Electric Company Car at 3% BIK
If you need a company car, choosing an electric vehicle in 2025-26 means a BIK rate of just 3% versus 30–37% for petrol/diesel cars. A £35,000 electric car creates only £1,050 of taxable BIK annually (£210 extra tax for a basic rate taxpayer). The equivalent petrol car at 30% creates £10,500 BIK (£2,100 extra tax). That is a £1,890 per year saving on the car alone — before considering fuel or charging costs.
10. Pension Carry-Forward
If your income has spiked in a particular year (business sale, large bonus, inheritance), use pension carry-forward to make a much larger pension contribution than the current year's £60,000 allowance. You can carry forward unused allowance from the previous three tax years (provided you were a registered pension member in those years) — potentially up to £180,000 in a single year. At 40% tax, this could shelter £72,000 of tax in one year.
Frequently Asked Questions
Is tax avoidance legal in the UK?
Using HMRC-approved reliefs — pensions, ISAs, allowances — is completely legal and encouraged. Aggressive avoidance schemes exploiting loopholes risk GAAR challenge. Tax evasion (hiding income) is always illegal.
What is the best way to save tax?
For most employees: salary sacrifice into a pension (saves income tax and NI simultaneously). For higher rate taxpayers, pension contributions at 40% relief are particularly powerful. After pension matching, ISA contributions prevent future tax on growth.
Do I need an accountant to reduce tax?
For most employed people, no — pension salary sacrifice, ISA contributions, Marriage Allowance and trading allowance can all be handled through your employer or HMRC online. An accountant adds value for self-employment, rental income, income above £100,000, or complex investment portfolios.