Investment platforms offering measly interest rates on cash holdings – is your cash working hard enough?
The interest rate on cash you hold within an investment account can be as low as 0.75%. We look at the worst cash rates on the market, and what you should do with your cash instead.
When growing your money in the long term, investing can be a good way to maximise your returns.
While the top savings rates have been as high as 5% in recent months, they are now falling as the Bank of England has continued to ease interest rates.
That means that the growth your cash savings will achieve may continue to get lower, especially at a time when inflation has been consistently above the 2% target.
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In the long run, investing your money tends to be better than saving it in cash. In the year to November 2025, the average stocks and shares ISA achieved returns of around 15.19%, data from Moneyfacts shows.
In the same period, the average cash ISA savings rate was around 3.7%.
Note that the value of your investments can go down as well as up, when investing.
While investing typically brings about better returns in the long run, some investors choose to keep some cash holdings in their investment accounts, perhaps because they have just sold some of their holdings and are waiting to invest them again.
The difficulty here is that holding cash with an investment platform will often mean you are earning far less interest than if you held that same cash in a savings account.
Analysis by MoneyWeek found some investment platforms are paying as little as 0.75% on cash holdings – that is 3.75 percentage points lower than the current best savings account on the market.
We look at the top interest rates available when holding cash with your investment platform, and where you could keep it instead.
How much interest will I get on cash in my investment account?
The level of interest you will earn on your uninvested cash within an investment account will differ depending on the platform you use.
However, what can be seen from the 10 platforms we analysed is that none of them will provide a cash interest rate better than the top savings accounts on the market.
Barclays Smart Investor
Customers using Barclays Smart Investor can hold cash within their account – though the rate of interest is measly.
Unless you opt out, the excess cash from your Investment ISA is moved into an Investment Saver account, where it will earn 1.06% interest.
That is not only far lower than the best savings rates on the market, it is also significantly lower than inflation, meaning your cash holdings will lose value in real terms.
Customers who hold a self invested personal pension (Sipp) with the service do not fare much better. Cash within a SIPP will earn just 1.66% interest, only marginally more than the Investment ISA rate.
The interest is paid on the first day of each month, based on the cash held in the account the previous month.
Charles Stanley Direct
Charles Stanley Direct has different cash interest rates depending on the amount of cash you deposit and the currency it is in.
For sterling deposits, you can earn a gross rate of interest of 1.25% between £0 and £99,999. For deposits over £100,000, you earn a gross rate of 1.65%.
For dollar deposits, the gross rate is 1.55% on deposits between $0 - $119,999. Deposits over $120,000 earn a rate of 1.65%.
Interest is calculated daily and paid biannually. The rates are the same for general investment accounts, stocks and shares ISAs, and Sipps.
Hargreaves Lansdown
The UK’s largest investment platform, Hargreaves Lansdown, pays an interest rate on cash held within its investment platform.
If you have a stocks and shares ISA you will earn a different interest rate depending on how much you hold within the account.
You will earn 1.51% on cash balances between £0 and £19,999, 1.18% between £20,000 and £99,999, 2.02% between £100,000 and £999,999, and 2.38% on balances worth £1 million and higher.
If you are investing in a fund or share account, you can expect different interest rates. They are: 1.26% up to £19,999, 1.46% between £20,000 and £99,999, 1.66% between £100,000 and £999,999, and 1.97% on balances £1 million and above.
Interest rates on Sipps and junior Sipps are better. You will earn 2.07% on cash balances up to £19,999, 2.27% between £20,000 and £99,999, 2.48% between £100,000 and £999,999, and 2.78% on balances worth £1 million and higher.
These rates will also differ for junior ISA, Lifetime ISA, and accounts using Hargreaves Lansdown’s portfolio management service. The full list can be found on Hargreaves Lansdown's website.
Interest is calculated on the daily cleared balance and is paid monthly.
Hargreaves Lansdown also offers an Active Savings service that allows you to move cash out of your investment accounts and enjoy better rates from banks it partners with.
Interactive Investor
Interactive Investor (ii) also pays interest on cash balances held in ISAs, Sipps, and trading accounts.
For ISAs and junior ISAs, it now pays 1.11% on the first £20,000, 1.26% on the value between £20,000 and £50,000, 1.36% between £50,000 and £100,000, and 2.21% on the value above £100,000.
Sipp users with cash in sterling can get 1.71% on the first £20,000, 2.21% on the value between £20,000 and £50,000, 2.22% between £50,000 and £100,000, and 2.32% over £100,000.
For cash in dollars the rates are 1% on the first £10,000, 1.76% on the value between £10,000 and £100,000, and 2.02% above £100,000.
Trading accounts now pay between 0.8% and 1.81% depending on the size of the cash balance in sterling. The rates differ for dollar holdings. The full list of rates can be found on ii’s website.
Interest on all accounts is calculated each day and credited on or around the 25th of each month.
AJ Bell
AJ Bell pays interest on cash balances from Sipps, junior Sipps, stocks and shares, lifetime, and junior ISAs, and dealing accounts.
Sipp and junior Sipp investors can get 2.05% interest on cash balances up to £100,000, and 2.4% on balances above £100,000. These rise to 2.65% and 3.15%, respectively, for Sipps in drawdown.
Stocks and shares ISAs, lifetime ISAs, and junior ISAs will earn 1.75% interest on all cash balances.
For dealing accounts, the interest rate is 0.75% up to £2,000 and 0% on cash holdings above £2,000.
Interest is calculated daily, based on the cleared cash in your account.
AJ Bell Dodl
Dodl, a beginner-focused investing app by AJ Bell, pays a much higher (and simpler) interest rate on cash holdings than its parent company.
All cash in your investment ISA or Lifetime ISA that you have not yet invested earns 3.8% variable interest.
Interest is calculated daily, based on the cleared cash in your account.
While the cash interest rate is strong, even when compared with the top savings account on the market, Dodl is a pared-back version of AJ Bell so you don't get the full range and functionality that you would on other platforms – but it is worth considering if you’re a beginner investor.
Bestinvest
Bestinvest also offers a decent level of interest when compared to some of the other platforms listed above. It also pays just one flat level of interest, making calculating it much simpler.
You will earn 2.98% interest on cash holdings within any of your investment accounts.
Vanguard
Vanguard UK Personal Investor also has just one flat interest rate on cash holdings.
You will earn an interest rate of 1.85% on any cash you hold within any of Vanguard’s investment accounts.
Fidelity Personal Investing
Fidelity offers one flat interest rate on all cash holdings in any of Fidelity’s products.
The rate is a flat 2.22% and is available for ISAs, junior ISAs, investment accounts, Sipps, Junior Sipps, and cash management accounts.
Interest is paid monthly in arrears.
Trading 212
The investment app Trading 212 pays the joint-highest interest rate on uninvested cash of 3.8%, tying with Dodl.
Customers need to enable “interest on cash” in the app to qualify for this rate. The app can pay such a high rate as it holds the cash in qualifying money market funds as well as banks.
Interest is paid daily.
How to boost your interest rate
Many of the interest rates listed above are so low that your cash will not even grow in real terms as rising inflation will erode it away.
The major exceptions to this are Trading 212 and Dodl, which both offer inflation-beating rates of 3.8%.
But despite the 3.8% figure being strong, it is still lower than the best savings account.
If you want to make sure your cash is working as hard as possible for you, it is a good idea to consider putting it into a different account.
One option is to check if your investment platform also offers a savings service – like Hargreaves Lansdown’s Active Savings product – as you are likely to get a higher rate by moving your cash into it.
Details differ between the services, but most move your cash holdings into different accounts provided by banks and building societies your platform partners with.
The merit of this is that your cash is kept with your investing platform, meaning it should be easy to transfer it back into your investment account, stocks and shares ISA or Sipp when you're ready to invest it.
A growing number of platforms offer these services, including AJ Bell and Interactive Investor.
Otherwise you could consider moving the cash holdings out of your investment account and instead put them into one of the top savings accounts on the market.
Chase’s saver with boosted rate, the best easy-access account on the market right now, offers an interest rate of 4.5% for the first year it is open.
Meanwhile, those who are willing to lock their money away for a year can enjoy 4.25% interest by using DF Capital’s 1 Year fixed account.
If you haven’t used your full £20,000 ISA allowance yet, you could also consider putting it into a top cash ISA, ensuring your interest payments are not taxed.
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Daniel is a financial journalist at MoneyWeek, writing about personal finance, economics, property, politics, and investing.
He covers savings, political news and enjoys translating economic data into simple English, and explaining what it means for your wallet.
Daniel joined MoneyWeek in January 2025 and previously worked at The Economist in their Audience team. He read history at Emmanuel College, Cambridge and edited Cambridge's student newspaper, Varsity.
In his free time, he likes reading, walking around Hampstead Heath, and cooking overambitious meals.