Are money market funds safe?

Money market funds are among the safest investment types, but they are NOT risk-free. Key risks include: they're not FSCS protected (unlike bank savings accounts), the fund value can theoretically fall (though extremely rare for sterling funds), and returns can decrease if interest rates fall. However, they invest in very high-quality, short-term debt from governments and major financial institutions, and the risk of actual loss is very low. In the 2008 financial crisis, only one US money market fund 'broke the buck' — no UK sterling money market funds did.

How do money market fund returns compare to savings accounts?

Money market fund returns are typically slightly below the best savings account rates but above the average easy-access rate. In a 4.5% base rate environment, money market funds typically yield around 4.0–4.5% gross. The best easy-access savings accounts may beat this by 0.1–0.5%, but the gap narrows with larger sums and the convenience factor. The main advantage of money market funds is that they're accessible through investment platforms and can be held in ISAs and SIPPs alongside your other investments.

Do I pay tax on money market fund returns?

Yes — money market fund distributions are treated as interest for tax purposes and are taxed at your marginal income tax rate (20%, 40%, or 45%). You can use your Personal Savings Allowance (£1,000 for basic rate, £500 for higher rate, £0 for additional rate). If you hold the fund in an ISA or SIPP, returns are completely tax-free. Accumulation units (where income is reinvested) still count as taxable income in the year it's earned.

Money Market Funds Guide UK — Low-Risk Investing Explained | PocketWise

Q: What is a money market fund?

A money market fund is a type of investment fund that holds very short-term, low-risk debt instruments such as government Treasury bills, certificates of deposit, commercial paper, and short-term bonds. They aim to provide a return close to the Bank of England base rate while maintaining a stable value. They're used as a low-risk alternative to savings accounts, often by investors parking cash they want quick access to. They're not deposits — so they're not FSCS protected — but they're considered among the lowest-risk investments available.

Money Market Funds Guide UK — Low-Risk Investing Explained

How money market funds work in the UK, typical returns, risks, tax treatment, and how they compare to savings accounts, cash ISAs, and other low-risk options.

By PocketWise · 25 March 2026 · 3 min read

Money market funds are a popular way to earn interest on cash while keeping risk extremely low. Here’s how they work.

What Is a Money Market Fund?

Feature	Detail
Definition	Investment fund holding very short-term, low-risk debt
What it holds	Treasury bills, certificates of deposit, commercial paper, short-term bonds
Goal	Return close to the Bank of England base rate with high stability
Risk level	Very low — but not FSCS protected
Access	Same day or next day in most cases
Minimum investment	Typically £1–£100 on platforms
Typical yield	4.0–4.5% (gross, in a 4.5% base rate environment)

How They Work

Step	Detail
1	You invest money into the fund (via a platform or broker)
2	The fund manager pools money from all investors
3	Invests in short-term, high-quality debt instruments
4	Interest earned is passed to you as distributions (income units) or reinvested (accumulation units)
5	You can withdraw at any time (same day or T+1)

Popular UK Money Market Funds

Fund	OCF	Yield (approx.)	Min investment
Royal London Short Term Money Market	0.10%	~4.3%	£1 (via platform)
L&G Cash Trust	0.11%	~4.2%	£1
Vanguard Sterling Short-Term Money Market	0.12%	~4.3%	£100
Aberdeen Standard Liquidity Fund	0.10%	~4.3%	£1
BlackRock ICS Sterling Liquidity	0.10%	~4.3%	£1
Fidelity Cash Fund	0.15%	~4.1%	£1
HSBC Sterling Liquidity	0.10%	~4.2%	£1

Yields are illustrative and fluctuate with interest rates. OCF = Ongoing Charges Figure.

Money Market Funds vs Savings Accounts

Factor	Money market fund	Easy-access savings account
Typical return	4.0–4.5%	3.5–5.0% (best rates)
FSCS protection	No	Yes (up to £85,000)
Access	Same day / T+1	Instant
Risk	Very low (but not zero)	Zero (within FSCS limit)
Can hold in ISA	Yes	Yes (Cash ISA)
Can hold in SIPP	Yes	No (most SIPPs don’t offer deposit accounts)
Platform fee	0.1–0.45% of your balance	None
Rate changes	Tracks base rate closely	Bank can (and does) change rate without notice
Switching	Instant on same platform	May need to open a new account

When Money Market Funds Make Sense

Situation	Why
Cash within an investment platform	Earn interest on uninvested cash alongside your stocks and shares ISA/SIPP
Emergency fund within an ISA	Keeps the ISA tax wrapper while earning near-base-rate returns
Large sums over £85,000	Savings accounts are only FSCS-protected up to £85k — MMFs diversify across many institutions
Parking cash before investing	While you decide what to invest in
Corporate treasury management	Businesses parking cash reserves

When a Savings Account Is Better

Situation	Why
You want FSCS protection	Bank deposits are protected up to £85k
Small amounts (under £85k)	Savings account is simpler and protected
Not using an investment platform	Saves on platform fees
You want the best headline rate	Top savings accounts can beat MMFs by 0.2–0.5%
You want zero risk	MMFs can theoretically lose value (though extremely unlikely)

Tax Treatment

Tax situation	Treatment
Outside ISA/SIPP	Taxed as savings interest at your marginal rate
Personal Savings Allowance	£1,000 (basic rate) / £500 (higher rate) / £0 (additional rate)
In a Cash or Stocks & Shares ISA	Tax-free
In a SIPP	Tax-free (taxed on withdrawal as pension income)
Accumulation units	Income is still taxable in the year it’s earned (even though you don’t receive cash)
Capital gains	Generally none — fund value stays stable

Risks

Risk	Likelihood	Detail
No FSCS protection	N/A	If the fund collapsed, you could lose money
Fund value falls	Extremely rare	Sterling MMFs have never “broken the buck”
Interest rate falls	Possible	Returns drop when base rate falls
Counterparty risk	Very low	Risk that an issuer defaults on their debt
Platform risk	Very low	If your platform goes bust, your assets are ring-fenced
Inflation risk	Moderate	Returns may not beat inflation

How to Invest

Step	Detail
1	Open an account with an investment platform (Vanguard, Hargreaves Lansdown, AJ Bell, Interactive Investor, etc.)
2	Choose your account type (ISA, SIPP, or general investment account)
3	Search for the money market fund by name
4	Invest your chosen amount
5	Distributions are paid or reinvested automatically