Top 10 UK Tax Reliefs You Might Be Missing in 2025

Most UK taxpayers pay more tax than they need to. Not because the system is unfair (well, not entirely) but because they don't claim reliefs they're entitled to. HMRC won't chase you to give you money back. You have to know what's available and ask for it.

Here are ten reliefs worth checking for 2025/26. Some are worth a few hundred pounds, others could save you thousands.

1. Marriage Allowance

If you're married or in a civil partnership and one of you earns under £12,570, the lower earner can transfer £1,260 of their Personal Allowance to the higher earner. That saves the couple £252 a year in tax.

The higher earner must be a basic-rate taxpayer (earning under £50,270). It won't work if either of you pays higher or additional rate tax.

You can also backdate claims for up to four years, so if you've been eligible since 2021/22 and never claimed, you could get back over £1,000 in one go.

Apply on GOV.UK.

2. Working from home allowance

If your employer requires you to work from home (even part of the time), you can claim tax relief of £6 per week — that's £312 a year. You don't need receipts. The relief is flat-rate.

On a basic-rate taxpayer's income, that's a £62.40 tax saving. Not life-changing, but it takes two minutes to claim on GOV.UK, and it applies for the full year even if you only work from home occasionally.

Self-employed people can instead claim a proportion of actual household costs (heating, broadband, etc.) through Self Assessment.

3. Pension contributions

Every pound you put into a pension gets tax relief at your marginal rate. A basic-rate taxpayer putting in £100 only actually pays £80 — the provider reclaims £20 from HMRC automatically.

Higher-rate taxpayers get 40% relief, but you need to claim the extra 20% through Self Assessment. Many people forget this. If you put £5,000 into your pension last year and you're a 40% taxpayer, you could be owed £1,000 in unclaimed relief.

Salary sacrifice pension arrangements are even better — you save National Insurance too.

4. Personal Savings Allowance

You can earn interest on savings tax-free up to:

• £1,000 if you're a basic-rate taxpayer
• £500 if you're a higher-rate taxpayer
• £0 if you're an additional-rate taxpayer

With savings rates above 4%, it's easy to breach these limits if you hold more than about £25,000 in cash savings accounts. Keep an eye on it, and use ISAs to shelter any excess.

5. Trading allowance

If you earn under £1,000 a year from casual self-employment, you don't need to report it to HMRC. No tax return, no record-keeping. The income is just tax-free.

This covers things like selling on eBay, occasional freelance work, or tutoring on the side. Once you go over £1,000, you need to register for Self Assessment, but you can still use the £1,000 as a deduction instead of claiming actual expenses if that works out better.

6. Rent-a-Room relief

If you let a furnished room in your home, you can earn up to £7,500 a year tax-free. That's £625 a month with zero tax. If you share ownership, the limit is £3,750 each.

This applies to Airbnb income too, as long as the property is your main home. Above £7,500, you'll need to declare the income through Self Assessment, but you can choose between the flat-rate allowance and deducting actual expenses — whichever gives you a lower tax bill.

Details on GOV.UK.

7. Gift Aid

When you donate to charity through Gift Aid, the charity reclaims 25p for every £1 you give. But if you're a higher-rate taxpayer, you can also claim back the difference between basic and higher rate on your tax return.

A £100 donation costs the charity nothing extra, but you can reclaim £25 through Self Assessment. Over a year of regular giving, this adds up. Many higher-rate taxpayers don't realise they can claim this.

8. Tax-Free Childcare

For every £8 you pay into a Tax-Free Childcare account, the government adds £2. The maximum top-up is £2,000 per child per year (or £4,000 for disabled children).

Both parents need to be working and earning at least £167 a week (roughly £8,700 a year) but less than £100,000 each. Apply through Childcare Choices.

This is separate from childcare vouchers (which closed to new entrants in 2018). If you're still on the old voucher scheme, check whether switching would save you more.

9. Mileage allowance

If you use your own car for business travel (not commuting), you can claim:

• 45p per mile for the first 10,000 miles in a tax year
• 25p per mile after that

If your employer already pays you a mileage rate but it's less than 45p, you can claim relief on the difference. Say your employer pays 20p per mile and you did 5,000 business miles — you can claim tax relief on 25p × 5,000 = £1,250 of expenses. At 20% tax, that's a £250 saving.

Claim through Self Assessment or by writing to HMRC.

10. Capital Gains Tax annual exemption

You can make £3,000 in capital gains per year without paying any CGT. This applies to profit from selling shares, second properties, or other assets.

The exemption has fallen sharply (it was £12,300 as recently as 2022/23), so it's worth using deliberately. If you're sitting on investments with large unrealised gains, selling some each year to use your exemption — sometimes called "bed and ISA" if you rebuy inside an ISA — is a sensible strategy.

Making sure you claim everything

A few practical points:

• Check every April. Allowances and thresholds change. What applied last year might not apply now.
• Keep records. Receipts, mileage logs, donation confirmations. HMRC can ask for evidence.
• Use Self Assessment if you need to. Several of these reliefs (higher-rate pension relief, Gift Aid reclaims, mileage) require a tax return to claim the full amount.
• Run the numbers. Use our salary calculator to see how reliefs affect your actual take-home pay.

You're not trying to dodge tax. You're claiming what the rules say you can have. There's nothing clever about paying more than you owe.