Year-End Tax Planning: How to Maximise Your Savings Before April

The UK tax year ends on 5 April. Everything resets after that: your personal allowance, your ISA limit, your CGT exemption. If you haven't used them, they're gone. No carrying forward, no extensions.

Most people don't think about this until late March, then panic. Here's what to check now so you're not scrambling.

Your personal allowance

You earn £12,570 before paying any income tax. That's the 2025/26 personal allowance, and it's been frozen at this level since 2021.

Two things to check:

• Is your tax code right? A wrong code means you're either overpaying or underpaying. Check your payslip or log into your personal tax account.
• Are you married or in a civil partnership? If one of you earns under £12,570 and the other is a basic-rate taxpayer, Marriage Allowance transfers £1,260 of unused allowance. That saves the higher earner £252 a year. It's free to apply and you can backdate it four years.

ISA allowance: use it or lose it

You can put £20,000 into ISAs each tax year. Everything inside grows tax-free, no income tax on interest, no capital gains tax on growth, and no tax when you withdraw.

If you've got spare cash sitting in a normal savings account earning taxable interest, moving it into a Cash ISA before 5 April is a straightforward win.

Stocks and Shares ISAs make more sense for longer-term savings (five years or more), but the point is the same: use the allowance before it resets.

Lifetime ISA

If you're between 18 and 39, a LISA lets you save up to £4,000 a year with a 25% government bonus on top, that's up to £1,000 free. You can use it towards your first home (up to £450,000) or withdraw it after age 60.

The catch: withdraw for any other reason and you lose 25% of what you take out, which actually means you lose more than the bonus.

Pension contributions

Pension contributions are one of the most tax-efficient things you can do, and the annual allowance is generous: £60,000 for 2025/26 (or 100% of your earnings, whichever is lower).

Here's why pensions are worth prioritising before year-end:

• Basic-rate taxpayer: You get 20% tax relief automatically. Put in £80, it becomes £100.
• Higher-rate taxpayer: You get another 20% back through self-assessment. That £100 in your pension effectively cost you £60.
• Employer match: If your employer matches contributions, that's free money. Max it out if you can.

Worked example

Tom earns £52,000. He puts £5,000 into his pension before April. His pension provider claims £1,250 in basic-rate relief (making it £6,250 in the pot). Tom then claims £1,250 back through self-assessment. His £5,000 contribution actually cost him £3,750 and put £6,250 into his pension.

If you haven't used your full allowance in the previous three tax years, you can carry it forward. Worth checking if you've had a good year.

Capital gains tax

The CGT annual exemption is just £3,000 for 2025/26. That's not much. If you're sitting on investments with gains, consider:

• Selling enough to use your £3,000 exemption before April, then reinvesting if you want to hold the same assets.
• Transferring assets to your spouse before selling. Each of you gets £3,000, so that's £6,000 between you.
• Spreading sales across two tax years. If you sell some before 5 April and the rest after, you get two years' worth of exemptions.

Transfers between spouses and civil partners are tax-free, so this is straightforward planning, not a loophole.

More detail on CGT at GOV.UK.

Allowable expenses (self-employed)

If you're self-employed or freelancing, make sure you've claimed every expense you're entitled to before filing. Common ones people forget:

• Working-from-home costs (simplified flat rate: £6/week, no receipts needed)
• Professional subscriptions and memberships
• Software and tools
• Business mileage (45p per mile for the first 10,000)

Keep receipts. HMRC can ask for evidence up to six years back.

Family tax breaks

A couple of other things worth checking before 5 April:

• Tax-Free Childcare: If you have children under 12, you can get up to £500 every three months per child (£2,000/year). You pay in, the government tops it up 20%. Apply at GOV.UK.
• Marriage Allowance: Already mentioned above, but if you haven't claimed it, you can backdate to 2021/22.

The checklist

Action	Deadline	Potential saving
Max out ISA	5 April	Tax-free growth on up to £20,000
Top up LISA	5 April	Up to £1,000 government bonus
Pension contribution	5 April	20-45% tax relief
Use CGT exemption	5 April	Tax-free on first £3,000 of gains
Claim Marriage Allowance	Any time (backdate 4 years)	£252/year
Check tax code	Now	Prevents over/underpayment

None of this is complicated. Most of it takes an hour or two. The hard part is actually doing it before the deadline, not after.

For a quick look at how tax changes hit your take-home pay, try our salary calculator.