The 5 April ISA deadline is closer than it might feel. With just over a month left in the 2025/26 tax year, now’s the time to check whether you’ve made the most of your ISA allowance, and to make sure you’re not handing back an opportunity you won’t get again.
This year’s allowance is £20,000 per person. It sounds like a lot, but the rules are changing from 2027 in ways that make the decisions you take this tax year worth getting right.
Whether you’ve contributed nothing yet or just want to top up your ISA before the deadline, here’s what you need to know.
Your ISA allowance is use-it-or-lose-it
Unlike some tax reliefs, your ISA allowance doesn’t roll over. Whatever you don’t use by 5 April is gone. You can’t add it to next year’s limit and carry it forward. That’s worth bearing in mind if you’ve come into money recently.
If any spare funds from a bonus at work, an inheritance or the proceeds from a property sale are sitting in an ordinary current or savings account, they’re exposed to tax on any interest or growth they generate. Sheltering them inside an ISA before the tax year ends will protect them permanently, not just for now.
With around a month until this year’s ISA deadline, there’s still a reasonable window to act. The catch is that some ISA providers take several days to process new applications or incoming transfers, and a small number can take longer.
So, if you’re planning to open a new ISA, switch providers or make a large transfer, don’t assume you can leave it until the first week of April. The 5 April deadline doesn’t flex. If your money doesn’t arrive in time, it won’t be included in this year’s allowance.
Cash ISA or stocks and shares ISA: which should you use?
This is the question most people grapple with. The honest answer is that it depends on what the money is for.
Cash ISAs are straightforward. They protect your money, pay predictable interest, and you can usually access your funds when you need them. However, average ISA rates have fluctuated over the past couple of years, so if you opened your Cash ISA some time ago and haven’t reviewed it since, it’s worth checking whether you’re still getting a competitive rate. Switching providers is usually simple, and your ISA status stays intact.
For money you’re unlikely to need for five years or more, a stocks and shares ISA is worth considering. The value can fall as well as rise, so it isn’t suitable for funds you might need at short notice. But over the longer term, investing has historically outperformed cash savings by a meaningful margin, which matters if you’re thinking about building wealth for retirement or some other goal further down the line.
Many people find a combination of both works well. Cash for their shorter-term needs or as a financial safety net, with a stocks and shares ISA for longer-term growth. No rule says you must choose one or the other.
Couples: doubling up before the deadline
If you’re married or in a civil partnership, you each have your own £20,000 ISA allowance, meaning you could collectively shelter up to £40,000 before 5 April. It’s one of the more straightforward ways to reduce your household’s tax exposure. Yet it’s often overlooked, particularly in households where one partner tends to take the lead on financial decisions.
However, ISA allowances are individual. They can’t be pooled or transferred between spouses, so each person needs to act separately and in their own name. So, if your partner hasn’t yet contributed this tax year, or at all, now’s a good time to sort it out together.
What’s changing for Cash ISAs in 2027?
From 6 April 2027, the Government plans to introduce a cap on Cash ISA contributions for under-65s. If the legislation goes ahead as planned, savers under 65 will be limited to putting a maximum of £12,000 per year into a Cash ISA, rather than the current £20,000. The overall ISA allowance will stay at £20,000, so the remaining £8,000 can still go into a stocks and shares ISA, a Lifetime ISA or an Innovative Finance ISA, just not into cash.
People aged 65 and over won’t be affected. They’ll still be able to contribute up to £20,000 to a Cash ISA each year.
The thinking behind the change is fairly transparent. The Government wants to encourage more people to invest rather than save in cash. Whether that appeals to you or not, the practical implication is clear. If you’re under 65 and currently rely on your Cash ISA as your main savings vehicle, the 2025/26 and 2026/27 tax years are your last opportunities to put the full £20,000 into cash, if that’s your preference. If you’ve been meaning to explore investing for a while but haven’t got around to it yet, it’s a nudge worth heeding.
Practical tips with a month to go
The clock is ticking, and the 5 April ISA deadline will be upon us sooner than you think. To make sure you don’t miss out on the full benefits of your allowance for the 2025/26 tax year, here are a few steps to take right now.
First, check what you’ve already contributed this tax year. It sounds obvious, but many people lose track, especially if their contributions have gone in at different times or across different accounts. Be aware that exceeding your annual allowance triggers an HMRC penalty, so it’s worth double-checking before you top up.
Also, be careful about opening a second ISA of the same type. You can pay into only one Cash ISA and one stocks and shares ISA in any given tax year. Opening a duplicate account with a different provider offering a better rate without transferring your existing ISA first can create complications with HMRC. If you want to switch providers, do it through an official ISA transfer rather than withdrawing and redepositing.
Consider moving any savings that are sitting in ordinary accounts. If you have money in a standard savings account that’s generating interest above your Personal Savings Allowance, that interest is taxable. Moving those funds into an ISA before 5 April means any future interest or growth is sheltered from tax, not just this year, but every year going forward.
Don’t let indecision cost you your ISA allowance. If you want to put money into a stocks and shares ISA but aren’t sure where to invest it, you don’t have to decide immediately. Many providers allow you to hold cash within a stocks and shares ISA while you work out your investment choices. Getting the money in before the deadline preserves your allowance. Your investment decisions can follow.
Finally, think ahead to the next tax year. The 2026/27 tax year begins on 6 April. Setting up a monthly direct debit into your ISA from the start of the new tax year will help you spread your contributions throughout the year and remove the annual last-minute scramble. It also means your money can start working sooner. It’s a small habit, but it can make a big difference over time.
How can Glenrose Financial Planners help?
Making the most of your ISA allowance before 5 April is a good start, but it’s only one piece of the picture. ISAs work best when you consider them alongside your pension, investments and broader tax position. The proposed 2027 changes add another layer of planning worth thinking through sooner rather than later.
At Glenrose, our advisers can help you work out the right approach for your circumstances, whether that’s deciding between cash and investing, making the most of your combined allowances with your partner or spouse, or understanding how your ISA fits into your longer-term financial plan.
If you’d like to talk things through before the deadline, book a consultation with one of our advisers today.