Do you want to know which UK stockbroker has the most clients or customers? It’s an easy question to ask, but it’s very difficult to get hold of reliable information to make a good comparison.

What counts as a UK stockbroker?

We must begin by clarifying what we term a ‘UK stockbroker’. For the purposes of this article, a UK stockbroker is a financial services firm which is either:

1. Registered as a company in the UK and regulated by the Financial Conduct Authority (FCA), or;
2. Registered as a company within the European Union, and is permitted to conduct financial services business in the UK by the FCA.

Prior to Brexit, European brokers operating in the UK did so under a ‘passporting’ arrangement. Post-brexit, any services made into the UK by a European company is subject to the trade deal which was agreed in December 2020.

We have deliberately included both British and European companies because to all intents and purposes, both of these groups of companies can operate in a similar manner regardless of their domicile, thanks to the previously extant free market, and the recent trade deal going forwards.

Please be aware that many international stockbroker groups may establish a UK subsidiary company which would fulfil these criteria. Therefore you may find US or Canadian stockbroking groups listed below.

How we measured the number of clients of UK stockbrokers

Stockbroker client data is not standardised, nor is it the subject of mandatory disclosures. Therefore, we have performed independent research to generate the data used in this report.

As the data sources are varied, and assumptions have been used, this data may be out-of-date, incomplete or not directly comparable. For example, sometimes the only available client numbers are global rather than UK-specific.

However, we hope that the list below helps investors understand who the ‘big players’ are, versus the small upstarts.

This is not immediately apparent from a glance at stockbroker websites, and therefore we feel this is critical information worth putting into the hands of retail investors.

List of largest UK stockbrokers by number of clients

Hargreaves Lansdown – 1,500,000 clients (UK – Stockbroking only)

Source: HL official website

Regardless of how you cut the data, Hargreaves Lansdown is the clear front runner in the race to be the largest UK stockbroker. With over £100 billion assets under administration, across its ISA, SIPP and funds & shares account types.

An interesting consequence of HL’s size is that many of its customers will also own a small share of the business. This is because the broker is large enough to be a constituent of the FTSE 100 index of large UK companies. Therefore any retail investors which invest in UK equity ETFs will likely have exposure to the company through their portfolio.

Interactive Investor – 350,000

Source: Interactive Investor official website

This acquisitive Manchester-based stockbroking business increased its size through a series of deals, one of which was to acquire the TD Direct Investing UK business in 2018 for £64m.

Interactive Investor claims to be the largest ‘flat fee’ broker available in the UK. This means that the account and trading fees are a fixed price which doesn’t increase with the size of a client’s investment portfolio. This pricing structure is often attractive to larger investors, who enjoy economies of scale through a flat-fee model.

AJ Bell – 312,300 clients (UK)

Source: AJ Bell official website

AJ Bell is another UK-based stockbroking powerhouse on this list. With £62.5bn of assets under management, AJ Bell is vast in both its current scale and its annual growth since it was founded in 1995.

This UK stockbroker is also publicly traded, like HL. AJ Bell is quoted on the London Stock Exchange (Ticker: AJB), and at the date of writing was a member of the FTSE 250 index.

Vanguard Investor – 150,000 clients (UK – Stockbroking only)

Source: FN News September 2020 – https://www.fnlondon.com/articles/vanguard-uk-retail-funds-almost-double-to-4bn-in-year-of-volatility-20200928

Vanguard launched its UK investing service in 2017 to great fanfare. Although we need to make clear that Vanguard Investor is not offer the same ‘execution-only broker’ breadth of choice that you find with HL, II and AJ Bell. That’s because investors on Vanguard’s home-grown platform are restricted to Vanguard-managed funds.

Barclays – 24,000,000 clients (UK – Banking & Investing services)

Source: Barclays PLC 2018 CEO Review – https://home.barclays/content/dam/home-barclays/documents/investor-relations/reports-and-events/annual-reports/2018/full-uk-ceo-review.pdf

While Barclays’s headline customer figure is high, this is because it is one of the UK’s largest banks. Barclays offers mortgages, current accounts as well as Barclays Investor, its stockbroking service. You may also be aware that Barclays offers credit cards under the Barclaycard brand.

This is why the attention-grabbing 24m figure does not earn Barclays a position at the top of this broker list.

The Share Centre – Between 227,000 – 265,000 (UK – Stockbroking only)

Source: 2009 – 2018 acquisition press release reports

The Aylesbury-based stockbroker The Share Centre was launched in 1991 and was recently acquired by Interactive Investor for £62m. It touted flat-rate pricing, although its current investors will be moved to a % fee model as they are moved under the Interactive Investor pricing model.

Should you pick a stockbroker based on the one with the most clients?

Having revealed the largest stockbrokers by clients, it’s important to reflect upon the other factors that make stockbrokers great:

• Execution times
• User-friendly interfaces
• Low share-dealing fees and investing costs
• Intuitive UK investing apps
• Low account charges
• Reliable customer service
• A wide range of investment & markets
• A tax-efficient stocks & shares ISA offering
• Access to participate in initial public offerings (IPOs)
• The financial stability of the firm
• Whether the firm has a reputation of treating its customers fairly

When we compare the best UK stockbrokers, we’re assessing many of these factors, rather than just counting the number of customers. As we’ve explained above, stockbrokers can often gain size by merely merging or acquiring its competitors. This isn’t necessarily a sign of great customer service, but rather advantageous access to venture capital or financing.