If you’ve been happily tucking money away into a Cash ISA each year, enjoying tax-free interest with no fuss, there’s something important on the horizon.

The government has confirmed some significant changes to how ISAs will work, and while they won’t come into effect until 6 April 2027, they’re worth understanding now.

These reforms will affect how much you can save in cash, introduce a new tax that doesn’t currently exist, and remove some of the flexibility ISA savers have enjoyed for years.

Let’s break it all down.

First, a Quick Reminder: How ISAs Work Today

An ISA – Individual Savings Account – is a tax-efficient wrapper for your savings or investments. Any interest you earn in a Cash ISA, or any growth in a Stocks and Shares ISA, is completely tax-free.

Each tax year, you get a £20,000 ISA allowance. You can split this however you like across different types of ISA:

  • Cash ISA – for straightforward savings
  • Stocks and Shares ISA – for investments like funds, shares, and bonds
  • Innovative Finance ISA – for peer-to-peer lending
  • Lifetime ISA – for first-time buyers or retirement (with a 25% government bonus)

The flexibility has always been one of the best things about ISAs. If you wanted to put the full £20,000 into cash, you could. If you wanted to split it between cash and investments, that was fine too.

That’s about to change.

What’s Changing from 6 April 2027?

There are four key changes coming. Let’s take them one at a time.

A New Cap on Cash ISA Contributions for Under-65s

The overall £20,000 annual ISA allowance isn’t changing. But if you’re under 65, you’ll only be able to put a maximum of £12,000 into a Cash ISA each tax year.

That’s a £8,000 reduction from what you can do today.

If you want to use your full £20,000 allowance, the rest will need to go into a Stocks and Shares ISA or an Innovative Finance ISA.

For people who prefer the simplicity and security of cash, this is a significant shift. It means being pushed towards investments, whether you’re comfortable with that or not.

Over-65s Are Exempt

If you’re 65 or over, these new restrictions won’t apply to you.

You’ll still be able to put the full £20,000 into a Cash ISA each year if you wish, just as you can today.

The thinking behind this exemption is that older savers may be less willing, or less able, to take on investment risk, and it wouldn’t be fair to force them into the stock market.

It’s a welcome recognition that one size doesn’t fit all.

A New 22% Tax on Cash Held in Investment ISAs

This is the change that’s caught a lot of people by surprise.

Currently, if you have a Stocks and Shares ISA, any cash sitting in the account – waiting to be invested, or just held as a buffer – earns interest completely tax-free, just like a Cash ISA.

From April 2027, that’s changing.

Any uninvested cash held inside a Stocks and Shares ISA will be subject to a 22% tax on the interest earned.

Why? Because the government wants to stop people getting around the new Cash ISA limits by simply parking their cash in an investment ISA instead.

It’s a significant shift. For the first time, money inside an ISA wrapper won’t be fully protected from tax.

If you’re someone who likes to keep a cash buffer in your investment ISA — perhaps while you decide what to buy, or as a safety net, you’ll need to think carefully about how much you leave sitting there.

Restrictions on Transfers

Here’s another change that reduces flexibility.

From April 2027, you won’t be able to transfer money from a Stocks and Shares ISA (or other non-cash ISAs) into a Cash ISA.

Transfers the other way – moving money from a Cash ISA into an investment ISA – will still be allowed.

This might sound like a small detail, but it matters. At the moment, if your circumstances change and you decide you’d rather have your money in cash, you can transfer it across. That option is being taken away.

It’s another nudge towards keeping money invested, even if your situation or attitude to risk changes over time.

Why Is the Government Doing This?

The government’s stated aim is to encourage more people to invest, rather than holding large amounts of cash. The argument goes like this: Over the long term, investing in the stock market has historically delivered better returns than cash savings. By nudging people towards investments, the government believes it’s helping them build more wealth over time.

There’s also a practical reason. Money invested in shares and funds flows into businesses, supporting economic growth. Money sitting in cash doesn’t do that in the same way.

But here’s the thing: Investing comes with risk. The value of your investments can go down as well as up, and there’s no guarantee you’ll get back what you put in.

For people saving for short-term goals like a house deposit, a new car, or a wedding, cash makes a lot of sense. For those who simply don’t feel comfortable with the ups and downs of the stock market, being pushed towards investments can feel unsettling.

Not everyone wants to invest, and not everyone should.

Who Will Be Most Affected?

These changes will have the biggest impact on:

  • Cautious savers under 65 who prefer to keep their money in cash
  • People building emergency funds who want easy access and no risk
  • Short-term savers putting money aside for goals in the next few years
  • Anyone who keeps cash in their Stocks and Shares ISA as a holding area before investing
  • People who value flexibility and like the option to move money between ISA types

If you’re a confident investor who already uses most of your allowance for stocks and shares, these changes might not affect you much. But for millions of people who rely on Cash ISAs, it’s a different story.

What Can You Do Now?

The good news is that you have time. These changes don’t come in until April 2027, so there’s no need to panic.

But that doesn’t mean you should ignore them. Here’s what you can do now:

Use your full Cash ISA allowance while you can

For the next couple of tax years, the current rules still apply. If you want to maximise your tax-free cash savings, now is the time to do it.

Review your overall ISA strategy

Take a step back and think about where your money is and whether it’s working hard enough for you. Are you making the most of your allowances? Is your money in the right place for your goals?

Think about your timeline

If you won’t need the money for ten, twenty, or thirty years, investing may well make sense, these changes or not. But if you need access to your money in the short term, cash is often the safer choice.

Don’t rush into anything

These changes are designed to nudge people towards investing. But that doesn’t mean you should jump into the stock market without understanding what you’re doing. Take your time, do your research, and make sure any decisions are right for you.

Consider getting advice

If you’re not sure how these changes affect your situation, it’s worth speaking to a financial planner. Everyone’s circumstances are different, and a good adviser can help you figure out the best approach for your goals and comfort level.

What This Means for Your Financial Plan

ISAs are a fantastic tool, but they’re just one piece of the puzzle.

The right mix of cash and investments depends on so many things: your age, your goals, when you’ll need the money, how you feel about risk, and what other savings or income you have.

A good financial plan takes all of this into account. It’s not about chasing the latest tax break or reacting to every government announcement. It’s about building something that works for you, whatever happens.

These ISA changes are a useful reminder to check in on your plans regularly. Rules change, life changes, and what made sense a few years ago might not be the best approach today.

The Bottom Line

From 6 April 2027, the ISA landscape is going to look quite different — especially if you’re under 65 and prefer cash savings.

The new rules bring:

  • A £12,000 cap on Cash ISA contributions for under-65s
  • A 22% tax on interest earned on uninvested cash in Stocks and Shares ISAs
  • Restrictions on transferring money from investment ISAs into Cash ISAs

These are significant changes, and they’ll affect millions of savers.

But you have time to prepare. Use it wisely.

Let’s Talk

If you’re wondering how these changes might affect your savings, your investments, or your overall financial plan, we’re here to help.

No jargon, no pressure – just a straightforward conversation about what makes sense for you.

Please note: This blog is for general information only and doesn’t constitute financial advice. Tax rules can change, and individual circumstances vary. Please speak to a qualified adviser before making any decisions. The value of investments can go down as well as up, and you may get back less than you invest.