How to Avoid Capital Gains Tax in the UK on Shares?

When you invest in shares, the goal is simple — to make a profit. However, when you sell those shares at a gain, the government may take a portion through Capital Gains Tax (CGT). While paying tax is part of financial responsibility, there are perfectly legal and strategic ways to reduce or even avoid Capital Gains Tax in the UK — especially on shares.

In this detailed guide, our experts at ABM Chartered Accountants explain how Capital Gains Tax works, what exemptions and reliefs are available, and which smart investment strategies can help you keep more of your profits in your pocket.

What Is Capital Gains Tax (CGT)?

Capital Gains Tax is a tax you pay on the profit (gain) made when you sell or dispose of an asset that has increased in value. It applies to assets like property, businesses, or shares.

For example, if you bought shares for £10,000 and sold them for £18,000, your gain is £8,000. Depending on your tax band and available exemptions, you may need to pay CGT on part of that amount.

In the UK, CGT is governed by HMRC, and the rates depend on your income level and the type of asset being sold.

Capital Gains Tax Rates on Shares (2025 Update)

As of the 2025 tax year:

• Basic rate taxpayers pay 10% on capital gains.
• Higher or additional rate taxpayers pay 20% on gains from shares and other chargeable assets.

Your total taxable income determines which band you fall into. The higher your income, the greater your CGT liability — which makes strategic tax planning essential.

The Annual CGT Exemption (Allowance)

Every individual in the UK receives an annual Capital Gains Tax allowance, known as the Annual Exempt Amount (AEA).

For the 2025/26 tax year, the AEA is £3,000. That means you can make up to £3,000 in capital gains in a tax year without paying any CGT.

This might sound small, but when combined with other reliefs and investment structures, you can substantially reduce your liability — or avoid CGT altogether.

Legal and Effective Ways to Avoid or Reduce Capital Gains Tax on Shares

Let’s go through the most practical and HMRC-approved methods to manage or reduce your CGT burden.

1. Use Your ISA Allowance

One of the simplest and most powerful strategies is to hold your shares in an ISA (Individual Savings Account).

All investments within an ISA are completely tax-free — meaning you pay no Capital Gains Tax when you sell shares and no Income Tax on dividends or interest earned.

For the 2025/26 tax year, you can invest up to £20,000 per person in an ISA. Married couples can combine allowances for up to £40,000 total tax-free investment.

Example:
If you bought £20,000 worth of shares in a Stocks & Shares ISA and sold them for £35,000, you keep the entire £15,000 profit — with no CGT due.

2. Maximise Use of Your Spouse or Partner’s Allowance

If you’re married or in a civil partnership, you can transfer shares to your partner without triggering Capital Gains Tax.

This strategy is particularly beneficial if your partner:

• Has unused CGT exemption allowance.
• Is in a lower income tax bracket.

By splitting ownership and gains between you, you can double your household exemption and potentially reduce your overall tax liability.

Example:
You make a £6,000 gain on shares. You transfer half the shares to your spouse before selling, meaning you both make £3,000 gains each — both within your annual exempt allowance. Result: no CGT payable.

3. Offset Gains with Losses

If you’ve made losses on some investments, you can offset those losses against your capital gains to reduce your overall taxable gain.

HMRC allows you to carry forward unused losses indefinitely, provided you report them in your self-assessment tax return.

Example:
You sold one batch of shares for a £10,000 gain but another for a £4,000 loss. You only pay CGT on the net gain of £6,000, not the full £10,000.

This is one of the easiest ways to reduce liability and should be part of every investor’s annual tax review.

4. Time Your Sales Carefully

Timing your share sales strategically can help you spread gains across multiple tax years — and make full use of your annual CGT exemption each year.

Example:
If you plan to sell shares with large gains, consider selling half before 5 April and the rest after 6 April. That way, you can utilise your tax-free allowance in two different tax years and effectively double your exemption.

5. Invest Through a Venture Capital Scheme

For high-net-worth investors or those willing to take more risk, HMRC offers several investment schemes that provide generous CGT reliefs, including:

Enterprise Investment Scheme (EIS)

• You can defer CGT on gains if you reinvest the proceeds into EIS-eligible shares.
• After three years, gains on EIS shares are completely tax-free if you meet the conditions.

Seed Enterprise Investment Scheme (SEIS)

• Designed for startups, it allows 50% Income Tax relief and 50% CGT reinvestment relief.

Venture Capital Trusts (VCTs)

• Dividends and capital gains from VCT shares are tax-free.

These schemes are more complex but can offer substantial tax advantages for investors willing to support early-stage businesses.

6. Give Shares as Gifts to Family Members

Transferring shares to family members (excluding your spouse) is considered a disposal for CGT purposes, meaning tax could still apply — but there are specific reliefs you can use, especially when gifting to children or for inheritance planning.

For instance, using Holdover Relief (under certain business or trust conditions) can defer the CGT until the recipient sells the asset.

This strategy can form part of a wider estate and inheritance tax plan, ensuring wealth is passed down efficiently.

7. Use Your Pension Allowance

Instead of selling shares and paying CGT, consider contributing to a Self-Invested Personal Pension (SIPP).

When you contribute to a pension, you receive Income Tax relief on the contributions — and the investments within the pension grow free from CGT.

It’s a double win: you reduce your taxable income and shield future gains from taxation.

8. Donate Shares to Charity

Donating shares to a registered UK charity not only supports a good cause but also gives you tax relief.

When you donate shares:

• You don’t pay CGT on the gift.
• You can claim Income Tax relief for the value of the donation.

This is a smart option for investors who want to reduce tax and make a positive social impact simultaneously.

9. Incorporate a Limited Company for Investments

If you frequently buy and sell shares, it may be worth establishing a limited company to hold your investments.

Companies pay Corporation Tax on gains rather than Capital Gains Tax, and the rates can be lower depending on profits.

You’ll also have more flexibility to reinvest profits without triggering personal tax liabilities immediately.

However, this route is complex and requires professional guidance from an experienced Canary Wharf Accountant like ABM Chartered Accountants, who can structure your company efficiently to align with HMRC requirements.

Capital Gains Tax Planning Example

Let’s illustrate how smart planning can save tax:

Scenario	Without Tax Planning	With Tax Planning
Gain on Shares	£20,000	£20,000
CGT Allowance	£0	£3,000
Losses Offset	£0	£2,000
Spouse Transfer	£0	£3,000 (spouse allowance)
ISA Investment	£0	£5,000 tax-free
Taxable Gain	£20,000	£7,000
CGT (20%)	£4,000	£1,400
Tax Saved	–	£2,600

By using a combination of exemptions, timing, and spouse allowance, the investor legally reduced CGT by over 65%.

Common Mistakes to Avoid

Even small errors can cost you extra tax or trigger HMRC penalties. Avoid these pitfalls:

1. Failing to report losses — unclaimed losses can’t be used later.
2. Ignoring your annual exemption — once the tax year ends, you can’t roll it over.
3. Mixing ISA and non-ISA investments — track each separately.
4. Poor timing of disposals — selling everything in one year can push you into a higher band.
5. Lack of professional advice — HMRC rules change frequently; expert guidance ensures compliance.

When Should You Pay CGT on Shares?

Capital Gains Tax on shares is reported and paid through Self Assessment. You must:

1. Report your gains by 31 January after the tax year ends.
2. Pay any CGT due by the same deadline.

You can also use HMRC’s real-time CGT service to report gains as you go.

Missing these deadlines can result in interest and penalties, so it’s always wise to stay organised — or let a professional handle it for you.

Why Professional Tax Planning Matters

Understanding and applying CGT exemptions is one thing — but optimising them for your specific portfolio, income level, and investment goals requires deeper expertise.

At ABM Chartered Accountants, we help individuals and businesses across London structure their investments to legally minimise tax. Our experienced accountants in Canary Wharf provide personalised advice on:

• CGT reporting and compliance
• Investment tax strategy
• Portfolio restructuring
• ISA and pension planning
• Limited company setup for investors

We ensure every client’s tax position is optimised while staying fully compliant with HMRC regulations.

Final Thoughts

Avoiding or reducing Capital Gains Tax on shares in the UK doesn’t require aggressive or risky tactics — it requires smart planning, awareness of exemptions, and professional guidance.

By leveraging your annual allowance, utilising ISAs, transferring to a spouse, and offsetting losses, you can legally protect your profits and build long-term wealth more efficiently.

If you’re looking for expert advice tailored to your situation, ABM Chartered Accountants can help you manage your tax affairs effectively and ensure your investments are working for you — not against you.

Need Help Managing Your Capital Gains Tax?

Speak to our expert team today for a free initial consultation.
📍 Located in the heart of London, our Canary Wharf Accountant team specialises in personal and business tax planning — helping you keep more of what you earn.