How To Buy Index Funds In The UK

To buy an index fund, you need an index fund investment platform account like Hargreaves Lansdown, AJ Bell or interactive investor. In this guide, we will explain what an index fund is, how they work, how you can pick the best ones and highlight where you can buy them

Best Index Fund Platforms Compared & Reviewed

In this guide we have ranked some of the best accounts for buying index funds in the UK. You can use our comparison of what we think are the best accounts for buying and selling index funds by dealing commission and ongoing account costs.

We have chosen what we think are the best index fund accounts based on:

  • over 40,000 votes and reviews in our annual awards
  • our own experiences testing the open-ended investment fund accounts with real money
  • an in-depth comparison of the features that make them stand out compared to alternative open-ended investment fund accounts.
  • interviews with the open-ended investment fund account CEOs and senior management

What is an index fund?

Index Funds track underlying markets and provide investors with a low-cost way to invest in a larger group of shares in one trade

An index fund is a type of investment fund that tracks the performance of a specific market index, such as the FTSE 100 or S&P 500, by holding the same mix of shares as that index.

In the UK, beginners can invest in index funds through online investment platforms or brokers like Hargreaves Lansdown, Vanguard, or AJ Bell by opening an ISA, SIPP, or general investment account and choosing a suitable fund.

Index funds

What are the best UK index funds to invest in for 2026?

A low-cost global tracker fund such as the Vanguard FTSE Global All Cap Index, the Legal & General Global Equity Index, or the HSBC MSCI World UCITS ETF could be a solid option for 2026. These products all provide exposure to thousands of stocks from a wide range of countries meaning that they offer a high level of diversification.

Another solid option is an S&P 500 or US stock market tracker fund such as the Legal & General US Index, the iShares US Equity Index, or the Vanguard S&P 500 UCITS ETF. Over the long term, the US stock market has generated exceptional returns for investors.

A third option is an emerging markets tracker product such as the iShares Emerging Markets Equity Index or the Vanguard Emerging Markets Stock Index. These kinds of products provide exposure to fast-growing countries such as India, China, Brazil, and South Korea.

How do you actually invest in index funds for beginners?

If you want to start investing in index funds, the basic steps are:

  1. Open an investment account with a reputable provider
  2. Fund the account with some savings
  3. Choose an index fund that suits your financial goals and risk tolerance
  4. Decide how much you want to invest in this fund
  5. Put in a trading order for the fund

It’s worth pointing out that when investing in index funds as a beginner, it’s smart to invest small amounts over time, instead of investing one large lump sum at once. By drip-feeding money into the market slowly, you can reduce the risk of investing at the top of the market.

What are the best index funds in the UK for beginners?

A low-cost global tracker fund is generally a good place to start when investing in index funds as a beginner. Examples here include the Vanguard FTSE Global All Cap Index, the Fidelity Index World, and the Legal & General Global Equity Index.

These funds provide exposure to thousands of stocks from a vast range of countries. So, they are the ideal foundation for an investment portfolio.

These products do have their risks. However, they are typically lower in risk than other products such as country-specific funds, sector funds, and thematic funds.

What are the best low-cost index funds in the UK?

A solid low-cost index fund in the UK is the Legal & General Global Equity Index. On Hargreaves Lansdown, this has an ongoing fee of just 0.08% (investors also need to pay platform fees).

In the ETF space, a low-cost fund that stands out is the Vanguard FTSE Developed World UCITS ETF, which has a fee of 0.12%. Note that with ETFs, many investment platforms charge lower annual account fees.

What are the top 5 index funds?

Identifying the top five index funds isn’t easy. Because data on these funds is a little opaque and top can be defined in many ways.

However, on Hargreaves Lansdown, the most popular ETF index funds as of July 2026 were:

  • Vanguard Funds Plc S&P 500 UCITS ETF USD
  • Vanguard Funds Plc FTSE All-World UCITS ETF (USD)
  • Vanguard Funds Plc S&P 500 UCITS ETF USD (GBP)

On the Interactive Investor platform, the most popular index funds in June 2026 were:

  • Vanguard FTSE Global All-Cap Index
  • HSBC FTSE All-World Index
  • Vanguard FTSE All-World ETF USD Acc
  • Invesco EQQQ Nasdaq-100 ETF GBP

On AJ Bell, the most popular index funds as of April 2026 were:

  • Fidelity Index World
  • HSBC FTSE All-World Index
  • iShares Core MSCI World UCITS ETF
  • HSBC MSCI World UCITS ETF USD

Are index funds a good investment?

For those investing for the long term, index funds are generally a smart investment. Over the long run, the stock market typically provides attractive returns and with these products, investors can get broad exposure to the stock market at a low cost.

It’s important to note, however, that with index funds financial gains are not guaranteed. If the stock market experiences a period of weakness, returns can be negative.

What is Warren Buffett’s favourite index fund?

While Warren Buffett is known for his stock-picking ability, he has often said that the vast majority of investors should stop trying to pick stocks and simply buy a low-cost S&P 500 index fund. Buffett’s view is that over the long term, investors in S&P 500 tracker funds should do well on the back of the growth of the American economy.

Examples of S&P 500 index funds include the Vanguard S&P 500 UCITS ETF (VUSA) and the iShares Core S&P 500 UCITS ETF (CSP1). These both aim to track the S&P 500 index, and they have low fees.

What are the big 3 index funds?

In the index fund world, the ‘big three’ are:

  • BlackRock (iShares)
  • Vanguard
  • State Street Global Advisors

Together, these firms dominate the index fund space, managing over $30 trillion in assets.

Note that each of these financial institutions offers many different index funds. Vanguard, for example, offers global funds, US funds, UK funds, emerging markets funds, and more.

Is a FTSE 100 or a S&P 500 index fund better?

If one is seeking long-term capital growth, an S&P 500 index fund could be a better option than a FTSE 100 index fund. Over the long run, the S&P 500 has outperformed the FTSE 100 by a wide margin due to its technology exposure, delivering a return of around 10% per year versus 7% for the Footsie.

However, if one is seeking dividend income, a FTSE 100 index fund could potentially be the better option. In this index, there are many high-yielding stocks and as a result, it has a higher yield than the S&P 500 (approx. 3% for the FTSE 100 versus 1% for the S&P 500).

How do index funds work?

The rise of passively managed investment funds has been the standout story of the last 25 years in the fund business.

Estimates differ, but as much as 30% of the money managed by funds globally is now believed to be invested passively in one way or another.

The two most common types are (a) index funds and (b) exchange-traded funds (known as ETFs).

The traditional way to manage an investment fund is for a qualified professional manager to choose a portfolio and monitor it on a daily basis, buying and selling individual securities on the basis of research and judgment, taking into account a range of factors, such as valuation, profitability, management competence and dividend potential. 

In contrast passively managed funds use a computerized approach to portfolio management, aiming to replicate the performance of a market index or to construct a portfolio with a pre-determined set of investment criteria.

This is a simpler and much cheaper method that academic research has shown often works just as well as actively managed equivalents.

What is the difference between index funds and exchange-traded funds?

Index funds are open-ended funds which issue units in the traditional way, directly to investors in response to investor supply and demand. They are typically valued and units issued or redeemed once a day.

Exchange-traded funds, in contrast, often have similar objectives but can be traded continuously like shares during market hours, with the portfolio being managed by investment banks and brokers rather than by a fund management company.

Another popular type of ETF are so-called “smart beta” funds which put together collections of securities that meet specified characteristics, such as a high dividend yield, low volatility or strong momentum.

What makes a good index fund?

Two qualities in particular are essential – low costs and low tracking error. You should expect a FTSE 100 index fund, for example, to mirror the performance of the FTSE 100 index very closely.

That after all is its purpose. In order to do that, as well as tracking efficiently, the fund will need to have very low charges – in general, the lower the better. The running costs of an index fund are much lower than those of a fund run by a human and competition to provide index funds has become very fierce in recent years.

Some tracker funds and ETFs charge as little as ten basis points as a management fee (in other words, the fee is equivalent to 0.1% or less of the value of your investment, compared to 1.0%-2.0% per annum for an actively managed fund).

What kind of performance should you expect from an index fund?

The whole point of an index fund is to provide you with the same return as whichever market, sector or type of investment you wish to own. The more mainstream the market, the more likely it is that you will be able to find a tracker fund that does what you want. For index funds that track leading developed market indices, the evidence is that the average index fund will produce reliable second quartile performance – that is to say, not among the very best performers in any one year, but normally ranked in the top 25% to 50% of comparable funds over longer periods.

The reason indexing has become so popular is the evidence that only a small minority of actively managed funds are capable of bearing their benchmarks consistently over periods of five years or more. Funds that do well in one year tend not to repeat the outperformance in future years. Persistence of outperformance, in other words, is poor. You have to be either skilled or lucky as an investor to pick the ones that do outperform consistently over longer periods. When taken together with their much lower costs, the reliable second quartile returns from an index fund make them an attractive practical alternative.

The Financial Conduct Authority, the City regulator, has published a number of studies emphasising the advantages of indexing as a strategy, based on academic research.  Remember though that an index fund is only a means to an end; how well your portfolio does will depend on its composition – how much you have in equities, fixed income, commodities, property, gold and so on. That decision remains down to you, or your financial adviser if you have one.

Are there index funds for all kinds of investment?

No. There are very few index funds that aim to track the performance of smaller companies and many emerging markets, for example, because dealing costs are too high and many securities are too illiquid to be traded cost-effectively. Index funds work best when they are competing against actively managed funds in liquid mainstream markets and sectors. They are useful as building blocks in a portfolio. This is where competition and transparency are most apparent. There is a broader range of ETFs; while most invest in indices, like index funds, ETFs also invest in commodities, currencies and certain investment styles and characteristics, such as volatility and momentum.

Are index funds rated?

Yes. For many years most brokers and platforms preferred to ignore index funds and ETFs, in part because they were less profitable to provide. However the increasing popularity of indexing as a strategy and the emergence of ETFs has forced research providers of all kinds to start rating passive funds as well, or in the case of platforms to put them on best buy lists. FE Trustnet for example rates 250 passive funds (both index funds and ETFs), noting that while passive funds are designed to replicate an index, “some prove much better at doing so than others”. Hargreaves Lansdown has 10 tracker funds on its Wealth 50 list of favoured funds.

Another way to screen index funds and ETFs is to look at the model portfolios which are now offered by many wealth management firms and platforms. Many of these use passive funds because they are cheap and easy to trade. Here is one of many possible examples you might look to for leads: Interactive Investor’s low cost growth portfolio. (Note that if you ask the firm to manage this portfolio for you, it will cost you additional fees; this is not a recommendation, just an illustration).

Source: Interactive Investor.

Which index funds are most popular?

It is not easy to find reliable figures on the best selling index funds. The market is however dominated by a small number of firms which are large enough to benefit from the economies of scale available from running the biggest funds. The biggest UK sellers include Blackrock, Legal & General, Fidelity and Vanguard. Index funds now account for roughly 15% of all open-ended funds sold in the UK. Their market share has doubled in the last 10 years.

Most of their sales are concentrated in funds that track mainstream UK, US and overseas market indices. The same is broadly true of ETFs, judging by the best sellers on specific platforms  (examples: clients of Hargreaves Lansdown and Barclays’ Smart Investor service). Notable providers in Europe include Blackrock (which owns iShares), Vanguard, Fidelity and Lyxor.

What is the secret to using index funds?

If you understand their strengths and limitations, passive funds are a simple and cost-effective way to construct a diversified portfolio that meets your objectives and tolerance for risk. Their growing popularity in recent years illustrates how investors have become more aware of the limits of actively managed funds and the importance of minimizing costs to maximize returns. ETFs give you additional options for adding commodities, currencies and specific investment factors to your portfolio, but also carry additional risks: make sure you understand how they work before investing in one.

⚠️ FCA Regulation

All index fund platforms that operate in the UK must be regulated by the FCA. The FCA is the Financial Conduct Authority and is responsible for ensuring that UK index fund brokers are properly capitalised, treat customers fairly and have sufficient compliance systems in place. We only feature index fund investing accounts that are regulated by the FCA, where your funds are protected by the FSCS.

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