Why investing early this tax year could boost your ISA

You probably know to top up your individual savings account (ISA) before the end of the tax year to make the most of your annual allowance.

But did you know that investing at the beginning of the tax year can turbocharge your investments over time?

Investor A: Puts in £20,000 (the current ISA allowance) on 6 April 2026, then does the same at the start of every tax year.

• Result after 25 years: £1,002,269 (assuming an annual return of 5% after fees)

Investor B: Waits and invests £20,000 each 5 April instead.

• Result after 25 years: £954,542 (assuming the same annual return)

Starting early leaves Investor A with nearly £50,000 more – simply from investing sooner each year.

Investing at the start of the tax year compared to the end

Notes: This hypothetical scenario is for illustrative purposes only and doesn’t represent a particular investment or its expected returns. It assumes annual returns of 5% after fees. Balances reflect the value at the end of each period.

Source: Vanguard calculations.

Invest early and often to grow your wealth

Our mission is to give investors the best chance of investment success, which is why we encourage early and consistent investing.

And the great thing about investing through an ISA is that you won’t pay:

• income tax on the dividends¹ or interest you receive

• capital gains tax on any profits you make when selling investments 

Of course, not everyone can invest £20,000 a year, let alone in one go. But if you have a lump sum of money that you don’t need for your emergency fund or short-term spending needs, consider investing it as soon as you can. After all, it’s time in the market, not timing the market, that counts. This is because history shows that patient investors tend to be rewarded over the long term.

If you don’t have a lump sum, you could take advantage of the new tax year by setting up regular payments or increasing them. At Vanguard, you can set up a Direct Debit, so you don’t have to remember to make a payment each month. 

The power of compounding boosts your ISA

One of the key reasons to invest early is that it gives you more time to benefit from compounding. This is when you earn returns on your returns, as well as on the money you invest. This can help your investments grow more quickly. 

It’s why Investor A earns almost an extra £50,000 by investing at the start of the tax year instead of at the end.

So, now that a new tax year has started, look at your finances to see whether you can top up your ISA now or set up a Direct Debit. Those extra 12 months could make a big difference to your wealth in the long run.
 

¹ Dividends are the payments some companies make to their shareholders out of their profits.
 

Investment risk information

The value of investments, and the income from them, may fall or rise and investors may get back less than they invested.

Any projections should be regarded as hypothetical in nature and do not reflect or guarantee future results.

The eligibility to invest in either ISA or Junior ISA depends on individual circumstances and all tax rules may change in future.

Important information

Vanguard only gives information on products and services and does not give investment advice based on individual circumstances. If you have any questions related to your investment decision or the suitability or appropriateness for you of the product[s] described, please contact your financial adviser.

This is designed for use by, and is directed only at, persons resident in the UK.

The information contained herein is not to be regarded as an offer to buy or sell or the solicitation of any offer to buy or sell securities in any jurisdiction where such an offer or solicitation is against the law, or to anyone to whom it is unlawful to make such an offer or solicitation, or if the person making the offer or solicitation is not qualified to do so. The information does not constitute legal, tax, or investment advice. You must not, therefore, rely on it when making any investment decisions.

Issued by Vanguard Asset Management Limited, which is authorised and regulated in the UK by the Financial Conduct Authority.

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