Investment Taxes UK 2025: Simple Guide to Dividend, CGT and ISA Rules

2025 UK Investment Tax: Dividends, Capital Gains & ISA Strategy in One Guide

Investment income has become increasingly important for UK households in 2025, as savings rates fluctuate and market volatility continues. Whether you invest through a general investment account, a Stocks & Shares ISA or a pension, understanding how dividends and capital gains are taxed is essential. With tax allowances shrinking and more people investing via apps such as Trading 212, Freetrade and Hargreaves Lansdown, knowing how to structure your portfolio can make a significant difference to your long-term returns.

This guide explains 2025/26 UK tax rules for dividends, capital gains and investment accounts, and shows how ISAs fit into your overall tax strategy. For a list of providers and current ISA offerings, see Best ISA Accounts UK 2025.

Dividend Tax in the UK (2025/26)

Dividends from UK and overseas shares are taxable unless held inside a tax-free wrapper such as an ISA or pension.

Dividend Allowance 2025/26: £500 per tax year

After the allowance, dividends are taxed as follows:

• Basic rate band: 8.75%
• Higher rate band: 33.75%
• Additional rate: 39.35%

Because the dividend allowance has been reduced repeatedly (from £2,000 → £1,000 → £500), more everyday investors now fall into dividend tax for the first time.

Capital Gains Tax (CGT) in 2025/26

CGT applies when you sell investments outside an ISA or pension and make a profit. Your CGT bill depends on the size of your gains and your total income.

CGT Annual Exempt Amount: £3,000 per tax year

CGT rates on shares and funds:

• Basic rate: 10%
• Higher/additional rate: 20%

Because the allowance has fallen sharply in recent years, more investors are now realising that regular rebalancing inside a General Investment Account may trigger a CGT bill.

Where should you hold your investments? (ISA vs GIA vs Pension)

Your tax position depends heavily on the type of account you use.

Feature	ISA	Pension (SIPP)	GIA
Tax on dividends	None	None	8.75% / 33.75% / 39.35%
Tax on capital gains	None	None	10% / 20%
Tax relief on contributions	No	Yes (20%–45%)	No
Withdrawal rules	Anytime, tax-free	From age 55–57+; taxable after 25% lump sum	Anytime; gains/dividends taxable
Annual limit	£20,000	Up to £60,000 (depending on income)	No limit
Best for	Tax-free long-term investing	Retirement saving	Short-term access & large portfolios

How ISAs protect your investment income

The main benefit of an ISA is that all dividends, interest and gains are completely tax-free. This means:

• No dividend tax, regardless of how large your holdings grow
• No CGT on selling shares or funds
• No need to report ISA activity to HMRC

2025/26 ISA Allowance: £20,000 per tax year

You can split this across:

• Stocks & Shares ISA
• Cash ISA
• Innovative Finance ISA
• Lifetime ISA (specific rules apply)

For current ISA rates and platforms, visit Best ISA Accounts UK 2025.

How dividends and capital gains work inside a GIA

If you invest through a General Investment Account (GIA), your returns may be taxable:

• Dividends: tax applies above the £500 allowance
• Capital gains: tax applies above the £3,000 allowance
• Losses: can be reported to HMRC and carried forward

GIAs are flexible and allow unlimited contributions, but long-term investors are increasingly moving as much as possible into ISAs to avoid rising investment taxes.

CGT planning: practical strategies for 2025/26

With the lower CGT allowance, more investors are using:

• Annual “bed and ISA” transfers: sell in the GIA to use your CGT allowance, then rebuy within an ISA
• Loss harvesting: realising losses to offset gains
• Spousal transfers: use both partners’ allowances and rate bands

These strategies can be especially helpful for investors with large holdings built up on low-cost trading apps.

Pension vs ISA vs GIA: which is best?

Your optimal mix depends on your time horizon, income and need for access.

Pension (SIPP) is usually best for long-term retirement saving because contributions receive generous tax relief.

ISA is ideal for medium–long-term investing where tax-free withdrawals matter.

GIA is suitable for short-term access, speculative investments or portfolios that exceed ISA limits.

Example: How investment taxes apply in practice

Scenario: You have £60,000 invested across ISA + GIA.

• £40,000 in Stocks & Shares ISA
• £20,000 in GIA

Annual return:

• Dividends: £1,200 total (£800 inside ISA, £400 inside GIA)
• Capital gains: £2,500 realised inside GIA

Tax treatment:

• ISA dividends: £0 tax
• GIA dividends: £400 – £500 allowance = £0 tax
• GIA capital gains: £2,500 – £3,000 allowance = £0 tax

This investor pays no tax because the ISA shelters most earnings and the GIA gains fall within the allowances.

FAQ: UK Investment Tax 2025

Do I need to report my ISA investments to HMRC?

No. ISAs are completely tax-free and do not need to be included on a Self Assessment return.

Are overseas dividends taxable?

Yes, unless held in an ISA or pension. Overseas dividends may also have withholding tax depending on the country.

Do I pay CGT every time I rebalance?

Only inside a GIA. No CGT applies inside ISAs or pensions.

Are platform fees deductible?

Not for individuals investing personally. Fees simply reduce your net gain.

Can I have both a SIPP and an ISA?

Yes. Most investors use both to balance flexibility and long-term tax efficiency.

Conclusion

The ongoing reduction in UK investment tax allowances means ISAs and pensions are more valuable than ever. By understanding how dividend tax, CGT and account types interact, you can structure your investments to minimise tax and maximise long-term returns. For help choosing the right ISA provider, visit Best ISA Accounts UK 2025.