The money market has been getting more attention from everyday investors and business owners than it has in years. With the Bank of England base rate elevated by historical standards, cash-like products that once felt barely worth bothering with are suddenly generating meaningful returns. Short-term money market funds saw over £1.3 billion of net inflows in a single month in late 2025, which tells you something about the shift in sentiment.

We think that is broadly a sensible response to the environment — but we also see a lot of business owners jump into financial products without fully understanding what they are holding, how the returns are taxed, or whether the product actually fits their needs. So before you move a chunk of your company cash or personal savings into a money market fund, it is worth taking five minutes to understand what you are actually dealing with.

The money market is not a place — it is a segment of the financial system where institutions, governments, and large investors lend and borrow money over very short time horizons, typically anywhere from overnight to twelve months. Instruments in this space include Treasury bills, certificates of deposit, commercial paper, and short-term government bonds.

When people talk about investing in the money market, they are almost always referring to a money market fund — a pooled investment vehicle that holds a diversified mix of these short-term instruments. The fund manager continually rolls the portfolio, keeping the average maturity very short, which is what gives the product its cash-like stability.

The key thing to understand is that money market funds are not bank accounts. They are investment products regulated by the FCA, and while they are low risk by the standards of the investment world, they are not covered by the Financial Services Compensation Scheme (FSCS) in the same way a savings account is. In practice the risk of loss is very low — but it is not zero, and it is worth understanding that distinction before you place a large sum.

The FCA is currently reviewing the regulatory framework for these funds, following Government plans to update the existing rules. The direction of travel appears to be broadly supportive of the sector, but it is another reason to stay informed rather than treating these products as a simple set-and-forget alternative to a bank account.

The appeal is straightforward: yields on short-term money market funds have been tracking closely with the Bank of England base rate. When the base rate was near zero, these products returned almost nothing. As rates rose, so did the yields on offer.

Looking at where major funds sit at the time of writing, the picture is competitive. Vanguard Sterling Short Term Money Market is yielding around 3.95%, Royal London Short Term Money Market around 3.90%, Fidelity Cash around 3.80%, L&G Cash Trust around 3.70%, and BlackRock Cash around 3.59%. These are not guaranteed — yields float with the market — but they give a sense of the current ballpark.

For context, many easy-access business savings accounts are offering similar or lower rates, often with more restrictive terms. So the argument for money market funds is partly about yield, and partly about flexibility — most allow same-day or next-day access, which matters if you are holding working capital or a tax reserve.

We would caution against assuming current yields are permanent. If the base rate continues to fall through 2026, yields on these funds will follow. Anyone deploying cash here should be doing so because the product fits their liquidity needs and risk tolerance, not because of a headline number that may look different in six months.

This is the question we get asked most often, and the honest answer is: it depends on what the cash is for and how long you can leave it untouched.

If you are a limited company with a meaningful cash reserve — perhaps retained profits sitting in your business account, or a pot set aside for your next corporation tax bill — a money market fund can be a sensible place to put that money to work while you wait. The yield is broadly comparable to the best business savings accounts, access is good, and the products are straightforward to hold through most business banking or investment platforms.

However, there are a few things worth thinking through first:

• Tax on investment income: Any returns earned inside your limited company will be treated as investment income and subject to corporation tax. This is not a reason to avoid the product, but it does mean the headline yield is not the after-tax yield.
• Liquidity timing: If you have a PAYE bill or VAT payment coming up, make sure your redemption timeline matches your payment deadline. Most funds are fast, but do not assume same-day if you need the cash immediately.
• Platform and custody: You will need a platform that allows business accounts to hold funds. Not all do. Check the setup before committing.

For business owners holding cash personally — whether as accumulated income you have not yet deployed, or savings sitting outside the company — the considerations are different and usually simpler, which we cover in the next section.

One thing many people do not realise is that money market funds can be held inside an ISA or a SIPP, which changes the tax picture significantly. If you hold a money market fund within a Stocks and Shares ISA, the yield accumulates free of income tax and capital gains tax. That is a meaningful advantage over holding the same fund in a general investment account, where the income will count towards your personal savings allowance and potentially be taxable beyond it.

There is a genuine question about whether a money market fund inside an ISA makes more sense than a cash ISA for some savers. The yields can be comparable, and some investors prefer the flexibility of being able to switch a money market fund holding into equities later without losing the ISA wrapper. If you are considering a transfer or new subscription, it is worth comparing what the best cash ISAs are currently offering against money market fund yields — neither is automatically better, and the gap tends to narrow and widen with rate movements.

For business owners who draw dividends and have accumulated personal savings, holding a money market fund within a Stocks and Shares ISA can be an efficient way to earn a return on cash you are not ready to invest more aggressively. It is not a dramatic strategy — it is simply making sure your money is not sitting idle when low-risk, accessible options exist.

If you are unsure how this fits with your overall tax position — for example, how it interacts with your capital gains tax position or personal allowance — that is something worth talking through with your accountant before moving significant sums.

Our overall view is that money market funds are a perfectly sensible tool for cash that needs to be accessible but should be earning something while it waits. They are not exciting, and they are not meant to be. They are a step up from letting cash sit in a current account earning nothing — no more, no less.

The areas we would flag for owner-managed businesses in particular are:

• Do not use money market funds as a substitute for proper cash flow planning. Knowing when your tax liabilities fall due, what your take-home pay looks like month to month, and whether your working capital is genuinely surplus — that planning comes first. A money market fund does not fix a cash flow problem; it just improves the return on cash you genuinely do not need right now.
• Watch rate movements. Yields on these funds are not fixed. As the Bank of England base rate adjusts, so will the returns. Anyone comparing today’s yield against a fixed-rate savings account should factor in that the money market fund yield may be lower in twelve months.
• FCA reform is ongoing. The regulatory framework for money market funds is being updated. There is no immediate cause for concern, but it is a reminder that these products sit within a regulated, evolving landscape — worth keeping an eye on if you hold significant sums.

For most SME owners, the money market is not a primary financial priority — getting your accounts in order, understanding your tax position, and planning ahead are far more impactful. But if you have idle cash and want to make it work a little harder, it is a reasonable option to explore.