Five Ways to Maximise Tax Year-End Planning Opportunities 2025/26

November 10, 2025

Smart financial moves to make before 5 April 2026. Discover how to maximise your ISA allowance, boost pension contributions, use personal allowances wisely, review inheritance tax planning, and manage capital gains effectively.

As the 2025/26 tax year-end approaches on 5 April 2026, UK taxpayers and investors have a critical window to maximise tax allowances, reduce liabilities, and strengthen their financial position. Tax year-end planning helps you make the most of government incentives before they reset, potentially saving thousands in tax whilst building long-term wealth.

Whether you're a high earner looking to optimise pension contributions, a dual-income household managing personal allowances, a property owner reviewing inheritance tax exposure, or an investor with capital gains to manage, taking action before the 5 April deadline ensures you don't leave money on the table. This guide covers five essential strategies to consider before the tax year ends.

What is tax year-end planning and why does it matter?

Tax year-end planning is the strategic review of your financial position in the weeks before 5 April to ensure you've used all available tax allowances and reliefs. The UK tax year runs from 6 April to 5 April the following year, and most allowances cannot be carried forward – use them or lose them.

Key allowances that reset on 6 April

Several valuable tax allowances reset annually, including the £20,000 ISA allowance, £60,000 pension annual allowance (or 100% of earnings if lower), £3,000 capital gains tax annual exempt amount, £3,000 inheritance tax annual gifting exemption, and £12,570 personal allowance with Marriage Allowance options.

Unused allowances disappear on 5 April, which means missing the deadline could cost you significant tax savings. For example, failing to use your full ISA allowance means losing the chance to shelter £20,000 from income tax and capital gains tax permanently.

How planning creates long-term value

Strategic year-end planning doesn't just save tax in the current year – it compounds over time. Money saved in ISAs grows tax-free forever, pension contributions benefit from decades of tax-free growth, and inheritance tax planning protects wealth for future generations. Regular year-end reviews create cumulative benefits that can dramatically improve your lifetime financial outcomes.

Who should prioritise tax year-end planning?

Tax year-end planning benefits almost everyone, but certain groups gain the most significant advantages from strategic action before 5 April.

High earners and higher-rate taxpayers

Those earning over £50,270 pay 40% income tax on earnings above this threshold. Pension contributions attract tax relief at your marginal rate, meaning every £60 contributed costs a higher-rate taxpayer just £36 after tax relief (with additional relief claimed through self-assessment). High earners can also face reduced personal allowances or loss of child benefit, making pension salary sacrifice particularly valuable.

Dual-income households

Married couples and civil partners can optimise by transferring assets to the lower-earning partner to use both personal allowances efficiently. The Marriage Allowance allows a non-taxpayer to transfer £1,260 of their personal allowance to a basic-rate taxpayer, saving up to £252 annually. Strategic asset ownership can also optimise capital gains tax and dividend allowances.

Investors and portfolio holders

If you hold investments outside tax wrappers, year-end planning helps you harvest capital gains within the £3,000 annual exempt amount, avoiding unnecessary tax on gains. Couples can effectively use £6,000 of exemptions by transferring assets between spouses, and strategic timing of disposals can spread gains across multiple tax years.

Business owners and self-employed

Business owners have flexibility to time income, bonuses, and dividends to optimise tax efficiency. Pension contributions reduce both personal income tax and corporation tax for limited companies, whilst ISAs provide tax-efficient saving for irregular income patterns.

Those approaching retirement

Pre-retirees can use final working years to maximise pension contributions with carry-forward rules, allowing up to three previous years' unused allowances to be used if you have sufficient earnings. Final salary years are critical for building retirement funds with maximum tax efficiency.

Five essential strategies for tax year-end planning 2025/26

These five core strategies cover the most valuable tax allowances expiring on 5 April 2026.

1. Make the most of your ISA allowance

Individual Savings Accounts (ISAs) remain the cornerstone of tax-efficient investing and saving. For both 2025/26 and 2026/27, the annual allowance is £20,000. Any returns earned within an ISA are completely free from income tax and capital gains tax, and there's no need to declare ISA income or gains on tax returns.

You can split your £20,000 allowance across different ISA types – cash ISAs, stocks and shares ISAs, innovative finance ISAs, or lifetime ISAs (with a £4,000 annual limit). Each tax year brings a fresh £20,000 allowance on 6 April, but unused allowances from previous years cannot be carried forward.

Action point: Review your current ISA contributions before 5 April 2026. If you haven't used your full £20,000 allowance, consider topping up with available savings or investments. Even a partial contribution shelters future growth from tax permanently.

2. Boost your pension contributions

Pensions offer the most generous tax relief available to UK investors. For 2025/26, you can contribute up to £60,000 annually or 100% of your earnings (whichever is lower). Contributions qualify for tax relief at your highest marginal rate – basic-rate taxpayers see £80 become £100 through automatic tax relief, whilst higher and additional-rate taxpayers can claim further relief through self-assessment.

Employer contributions also count towards the annual allowance but don't require personal income to qualify for tax relief. Those with unused allowances from the previous three tax years can use carry-forward rules to make larger contributions, provided they have sufficient earnings to support the claim.

Even non-earners can contribute up to £2,880 annually, receiving £720 government top-up, making a total contribution of £3,600. This makes pensions valuable for stay-at-home parents or those taking career breaks.

Action point: Calculate your total pension contributions for 2025/26, including employer contributions. If you haven't reached £60,000 and have available income, consider additional personal contributions or salary sacrifice before 5 April to maximise tax relief.

3. Use your personal allowance and Marriage Allowance wisely

Everyone receives a personal allowance of £12,570 for 2025/26 – the amount you can earn tax-free each year. Personal allowances cannot be carried forward, so unused allowances are lost at year-end. Strategic planning helps married couples and civil partners make full use of both allowances.

The Marriage Allowance lets a non-taxpayer transfer £1,260 of their personal allowance to a spouse or civil partner who pays basic-rate tax. This saves up to £252 in the 2025/26 tax year, and claims can be made retrospectively for up to four previous years – potentially recovering over £1,000 in past tax overpayments.

For couples where one partner earns significantly less, consider holding savings accounts or investments in the lower earner's name to reduce overall household tax liability. This works particularly well for dividend income and savings interest, keeping both partners below their respective tax thresholds.

Action point: Review household income allocation between partners. If one earns below £12,570 and the other pays basic-rate tax, claim Marriage Allowance. Consider transferring assets to optimise both personal allowances and dividend/savings allowances before year-end.

4. Review your inheritance tax position

Inheritance tax (IHT) is charged at 40% on estates exceeding £325,000 – the nil-rate band threshold frozen until April 2030. An additional £175,000 residence nil-rate band applies when passing your main home to direct descendants, potentially creating a combined £500,000 tax-free threshold (£1 million for married couples combining both allowances).

Year-end planning helps reduce future IHT liabilities through strategic gifting. Everyone has an annual gifting exemption of £3,000, which can be carried forward one year if unused. Small gifts of up to £250 per person (to unlimited recipients) are also exempt, alongside unlimited gifts from surplus income if they don't affect your standard of living and are properly documented.

Larger gifts become potentially exempt transfers (PETs), falling outside your estate if you survive seven years after making them. Taper relief reduces tax on gifts made 3-7 years before death. With pension funds set to be included in taxable estates from April 2027, reviewing your estate position before year-end becomes even more critical.

Action point: Calculate your potential estate value and IHT exposure. Use your £3,000 annual gifting exemption before 5 April, and if you didn't use last year's exemption, you can gift £6,000 this tax year. Consider regular gifts from surplus income if appropriate for your circumstances.

5. Manage your capital gains tax liability

The capital gains tax (CGT) annual exempt amount for 2025/26 is £3,000 (£1,500 for most trusts). Gains exceeding this threshold are taxed at 18% for basic-rate taxpayers (on gains falling within the basic rate band) and 24% for higher and additional-rate taxpayers (or basic-rate taxpayers where gains push them into the higher-rate band).

Couples can transfer assets to each other without triggering CGT, effectively creating a combined £6,000 annual exemption. Making strategic disposals before 5 April allows you to realise gains within your exemption, avoiding unnecessary tax in future years when you might sell larger positions.

Year-end is also the time to review loss-making investments. Capital losses can offset gains in the same tax year, with excess losses carried forward indefinitely to use against future gains. Crystallising losses before 5 April ensures they're available to reduce current-year tax bills.

Action point: Review investment holdings with unrealised gains. If you plan to sell positions in the next 12-24 months, consider whether realising up to £3,000 in gains before 5 April makes sense. Married couples should review asset ownership to optimise both exemptions.

The benefits of proactive tax year-end planning

Strategic year-end planning delivers multiple advantages beyond immediate tax savings.

Immediate tax savings

Using all available allowances reduces current-year tax liability. Maximising pension contributions can move you from higher to basic-rate tax, ISA contributions shelter investment returns from tax permanently, and CGT planning avoids unnecessary capital gains charges on disposals.

Long-term wealth compounding

Tax-free growth within ISAs and pensions creates compounding benefits over decades. A £20,000 ISA contribution growing at 6% annually becomes £32,000 in ten years – all tax-free. The same investment in a taxable account generates taxable gains and income, reducing net returns significantly.

Reduced administrative burden

Money held in ISAs doesn't need to be declared on tax returns, reducing admin and compliance risk. Pension contributions reduce taxable income, potentially removing the need for self-assessment entirely if they bring you below self-assessment thresholds.

Estate planning efficiency

Regular gifting within annual exemptions progressively reduces your estate's IHT exposure without waiting seven years for larger gifts to become exempt. Consistent year-end gifting creates measurable IHT savings over time.

Financial clarity and control

Annual year-end reviews force you to assess your overall financial position, track progress towards goals, and identify gaps in planning. This discipline creates better long-term outcomes than reactive decision-making.

Risks and limitations to consider

Tax year-end planning requires careful consideration of potential downsides and constraints.

Accessibility and lock-in periods

Pensions cannot normally be accessed until age 55 (rising to 57 from April 2028). Contributing significant sums close to retirement requires careful liquidity planning. ISAs remain accessible, but frequent withdrawals undermine long-term compounding benefits.

Investment risk and market volatility

Contributions to stocks and shares ISAs or pensions expose you to market risk. Rushed year-end decisions without proper asset allocation planning can lead to poorly timed investments during volatile periods. Cash flow must support contributions without creating financial stress.

Allowance tapers and thresholds

High earners with adjusted income over £260,000 face pension annual allowance tapering, reducing the £60,000 allowance by £1 for every £2 of income over this threshold (down to a minimum £10,000). Personal allowances reduce for those earning over £100,000, losing £1 of allowance for every £2 earned above this level.

Legislative changes and frozen thresholds

Tax allowances remain subject to government policy changes. The pension annual allowance has seen multiple changes in recent years, IHT thresholds are frozen until 2030 (creating fiscal drag as house prices rise), and CGT rates could change in future budgets. Planning must remain flexible to adapt to rule changes.

Complexity of carry-forward and retrospective claims

Using pension carry-forward rules requires careful calculation of previous years' earnings and contributions. Marriage Allowance retrospective claims involve HMRC admin. Errors in claiming relief or exemptions can trigger penalties or delayed refunds.

Tax considerations and compliance requirements

Understanding tax treatment and regulatory requirements ensures compliant, effective planning.

Tax relief mechanisms for pensions

Most workplace pensions use relief at source, where providers claim basic-rate relief automatically (turning £80 into £100). Higher and additional-rate taxpayers must claim further relief through self-assessment. Some employers use net pay arrangements, giving full relief automatically but providing no benefit to non-taxpayers.

CGT reporting and payment deadlines

Residential property disposals must be reported to HMRC within 60 days, with tax paid within the same timeframe. Other capital gains are reported via self-assessment by 31 January following the tax year-end. Accurate record-keeping of acquisition costs, disposal proceeds, and allowable expenses is essential.

IHT gift reporting and documentation

Whilst most lifetime gifts don't require immediate reporting to HMRC, executors must disclose gifts made in the seven years before death when applying for probate. Proper documentation of gift dates, amounts, and recipients is critical. Regular gifts from surplus income require contemporaneous records proving they don't affect your living standards.

ISA transfer rules and annual limits

You can transfer ISAs between providers without using your annual allowance, but transfers must follow proper procedures to maintain tax benefits. Withdrawing funds and re-depositing them can breach annual limits. Only current tax year contributions can be freely withdrawn and replaced within the same allowance.

FCA regulation and advice boundaries

Generic tax planning guidance differs from personalised financial advice. Regulated financial advisers must assess suitability before making personal recommendations. This article provides information only – your individual circumstances determine whether these strategies suit your specific position.

Real-world case studies: tax year-end planning in action

Case study 1: Sarah – maximising ISA and pension contributions

Profile: Sarah, 42, earns £75,000 as an IT consultant. She has £18,000 in cash savings earning 4% interest and contributes 5% to her workplace pension (employer adds 3%).

Challenge: Sarah pays higher-rate tax on £24,730 of income (£75,000 - £50,270). Her cash savings generate £720 annual interest, taxable at 40% above her £500 savings allowance (as a higher-rate taxpayer). She hasn't used her ISA allowance this tax year.

Actions taken before 5 April:

• Transferred £15,000 from cash savings into a stocks and shares ISA, invested in a diversified portfolio
• Increased pension contributions by £5,000 through salary sacrifice before year-end
• Used her remaining £5,000 ISA allowance for regular monthly contributions in the new tax year

Outcomes:

• Immediate tax saving: £5,000 pension contribution saves £2,000 in higher-rate income tax (40%)
• Future tax savings: £15,000 ISA contribution eliminates £600 annual tax on investment returns (assuming 4% return taxed at 40%)
• 10-year projection: £15,000 growing at 6% annually reaches £26,800 tax-free in an ISA vs £23,400 after tax in a taxable account – £3,400 additional wealth
• Total immediate tax saving: £2,000 + ongoing annual tax reduction

Case study 2: James and Emma – optimising household allowances and CGT

Profile: James, 55, earns £58,000. Emma, 53, stopped working to care for elderly parents, with no taxable income. They hold £80,000 in joint investment accounts outside ISAs showing £8,000 unrealised gains.

Challenge: James pays higher-rate tax on £7,730 of income. Emma's £12,570 personal allowance goes unused. Their joint investments generate taxable dividends and capital gains they're planning to realise when downsizing their home.

Actions taken before 5 April:

• Claimed Marriage Allowance, transferring £1,260 of Emma's personal allowance to James
• Transferred £40,000 of investments from joint ownership to Emma's sole name (no CGT on spousal transfers)
• Emma realised £3,000 in capital gains before year-end within her annual exempt amount
• James contributed an extra £7,000 to his pension via lump sum payment before 5 April
• Made a £6,000 gift to their daughter (using current and prior year's £3,000 annual exemptions)

Outcomes:

• Marriage Allowance saves £252 annually in income tax
• Emma's £3,000 CGT gain realised tax-free (vs £720 tax at 24% if James had sold)
• Future dividend income on £40,000 now uses Emma's £500 dividend allowance (vs James's already exhausted allowance)
• James's £7,000 pension contribution saves £2,800 in higher-rate tax relief
• £6,000 inheritance tax gift reduces estate IHT liability by £2,400 (at 40%)
• Total immediate tax savings: £252 + £720 + £2,800 = £3,772, plus ongoing annual dividend tax savings and estate protection

Frequently asked questions about tax year-end planning

What happens if I miss the 5 April deadline?

Unused allowances for ISAs, pensions (current year), capital gains exemptions, and IHT gifting allowances cannot be carried forward except where specific rules allow (e.g., pension carry-forward for previous three years' unused allowances, one year carry-forward for IHT annual gifting). Missing the deadline means permanently losing that year's tax-free opportunities. However, the new tax year starting 6 April brings fresh allowances to use.

Can I use both a cash ISA and stocks and shares ISA in the same tax year?

Yes. You can split your £20,000 annual ISA allowance across multiple ISA types – cash, stocks and shares, innovative finance, or lifetime ISAs (£4,000 limit). You can open multiple ISAs in a single tax year, but you can only contribute to one of each type per tax year. For example, you could put £10,000 in a cash ISA and £10,000 in a stocks and shares ISA, but not £10,000 in two different cash ISAs in the same year.

How do I claim higher-rate tax relief on pension contributions?

If your pension uses relief at source (most personal and workplace pensions), basic-rate relief (20%) is added automatically. Higher-rate (40%) and additional-rate (45%) taxpayers must claim extra relief through self-assessment tax returns. You report gross pension contributions on the return, and HMRC adjusts your tax code or sends a refund for the additional relief. Net pay pension schemes give full relief automatically regardless of tax rate.

What's the seven-year rule for inheritance tax gifts?

Gifts exceeding your annual exemptions become potentially exempt transfers (PETs). If you survive seven years after making the gift, it falls outside your estate completely for IHT purposes. If you die within seven years, the gift is added back into your estate valuation. Taper relief reduces tax on gifts made 3-7 years before death: 3-4 years (80% tax), 4-5 years (60% tax), 5-6 years (40% tax), 6-7 years (20% tax). Gifts within three years face full 40% IHT.

Should I prioritise ISAs or pensions for tax-efficient saving?

Pensions offer higher upfront tax relief (20%-45% depending on your tax rate) and employer contributions, but funds are locked until age 55-57. ISAs provide flexibility with immediate access and tax-free growth, but no upfront tax relief. Most people benefit from using both: pensions for long-term retirement saving where tax relief and employer contributions maximise value, and ISAs for medium-term goals or emergency funds requiring flexibility. Your age, income, retirement timeline, and liquidity needs determine the optimal balance.

Decision checklist: Is year-end tax planning right for you?

Use this checklist to identify whether you should take action before 5 April 2026:

• ☐ Have you contributed less than £20,000 to ISAs this tax year and have available savings to shelter from tax?
• ☐ Do you earn over £50,270 (higher-rate threshold) and haven't maximised pension contributions for tax relief?
• ☐ Are you married/in a civil partnership with one partner earning under £12,570 who hasn't claimed Marriage Allowance?
• ☐ Do you hold investments outside ISAs with unrealised gains under £3,000 per person you could realise tax-free?
• ☐ Have you used your £3,000 annual inheritance tax gifting exemption this year or last year?
• ☐ Do you have unused pension allowances from previous tax years and sufficient income to use carry-forward?
• ☐ Are you planning to sell investments or property in the next 12 months where strategic timing could optimise CGT?
• ☐ Do both partners in your household pay tax when asset ownership could be optimised?
• ☐ Have you reviewed whether salary sacrifice or lump-sum pension contributions make sense before year-end?
• ☐ Is your estate likely to exceed £325,000 (or £500,000 with residence nil-rate band) without proactive IHT planning?

If you've ticked two or more boxes, year-end tax planning could deliver significant benefits. The more boxes you tick, the greater the potential value of strategic action before 5 April 2026.

Next steps: Taking action before 5 April 2026

Tax year-end planning creates lasting value, but only if you act before the deadline. Here's how to move forward:

Review your current position

Gather information on ISA contributions made this year, total pension contributions including employer payments, current taxable income and tax rate, investments held outside ISAs with potential gains or losses, gifts already made in 2025/26, and estimated estate value for IHT planning.

Calculate available allowances

Determine remaining ISA allowance (£20,000 minus contributions already made), available pension allowance considering carry-forward if applicable, unused personal allowance or Marriage Allowance opportunities, and capital gains headroom within £3,000 annual exempt amount.

Prioritise actions based on your circumstances

Focus first on expiring allowances with the highest tax benefit relative to your situation. Higher-rate taxpayers typically gain most from pension contributions, whilst those with large cash holdings benefit most from ISAs. Couples should review joint optimization strategies.

Implement changes before 5 April

Transfer funds to ISAs, increase pension contributions via payroll or lump-sum payments, claim Marriage Allowance through HMRC online services, realise capital gains or crystallise losses where appropriate, and make IHT-exempt gifts within annual allowances.

Document decisions and set up ongoing planning

Keep records of all year-end actions for future tax returns and planning. Set calendar reminders for January–March each year to review upcoming year-end opportunities, avoiding last-minute rushed decisions.

Speak to a professional adviser

Year-end planning involves complex interactions between allowances, tax rates, and personal circumstances. Professional financial advice ensures your strategy aligns with long-term goals whilst maximising tax efficiency. Advisers can model scenarios, optimise pension carry-forward calculations, and coordinate multiple strategies for maximum benefit.

Taking control of your tax position before 5 April 2026 helps you reduce tax, grow wealth more efficiently, and build a stronger financial foundation for the future. Don't let valuable allowances go to waste – act now whilst time remains.

Glossary of key terms

• Annual Allowance: The maximum amount you can contribute to pensions each tax year whilst receiving tax relief (£60,000 for 2025/26)
• Annual Exempt Amount: The amount of capital gains you can realise each tax year without paying tax (£3,000 for 2025/26)
• Carry Forward: The ability to use unused pension annual allowances from the previous three tax years if you have sufficient earnings
• ISA (Individual Savings Account): A tax-efficient savings or investment account where returns are free from income tax and capital gains tax
• Marriage Allowance: A tax relief allowing a non-taxpayer to transfer £1,260 of their personal allowance to a basic-rate taxpayer spouse/civil partner
• Nil-Rate Band: The threshold below which no inheritance tax is charged (£325,000 for 2025/26)
• Personal Allowance: The amount of income you can receive each tax year before paying income tax (£12,570 for 2025/26)
• Potentially Exempt Transfer (PET): A lifetime gift that becomes exempt from inheritance tax if you survive seven years after making it
• Relief at Source: A pension contribution method where basic-rate tax relief is added automatically by the pension provider
• Residence Nil-Rate Band: An additional inheritance tax allowance (£175,000) when passing your main home to direct descendants

Author: David Gregory, Financial Planner & Director at Off-Piste Wealth. FCA authorised and regulated. Last reviewed: November 2025. Service areas: Financial planning, investment management, pension planning, inheritance tax planning.