To make the most of your ISA allowance at the last minute, check how much of the £20,000 you have already used, find your provider's own cut-off (often a few days before 5 April), pay in by debit card or Faster Payment rather than cheque, and move any existing savings by ISA transfer rather than withdrawal. Unused allowance does not roll over, so anything not paid in by 5 April is lost for good.
This is an evergreen checklist for the final weeks of any tax year. The current tax year ends on Monday 5 April 2027, and it matters more than usual: it is the last year under-65s can put the full £20,000 into Cash ISAs, before the cash limit falls to £12,000 from 6 April 2027.
Step 1: work out what you have left
Your £20,000 allowance covers new money paid into all your adult ISAs in the tax year combined: Cash ISAs, Stocks and Shares ISAs, Innovative Finance ISAs and Lifetime ISAs. Transfers of money saved in previous years do not count.
- Add up every payment you have made since 6 April, across all providers
- Remember that Lifetime ISA payments count towards the £20,000, up to £4,000 a year (the 25% government bonus does not)
- Junior ISAs have their own separate £9,000 limit per child
- If you replaced money withdrawn from a flexible ISA, that replacement does not use new allowance
- Our ISA allowance tracker adds it up for you
Step 2: check provider cut-offs
HMRC's deadline is 5 April, but many providers set earlier cut-offs for opening new accounts, accepting certain payments and processing transfers, especially when 5 April falls on or near a weekend or bank holiday. Check your provider's website for its exact dates; some publish them in March.
| Payment method | Typical speed | Last-minute suitability |
|---|---|---|
| Debit card | Usually instant | Best for the final days |
| Faster Payment | Usually within hours | Good, but check the reference |
| Cheque | Several days | Avoid near the deadline |
| Direct debit set-up | Can take weeks | Too slow |
Opening a new account can take time if the provider needs to verify your identity, so do it at least a week before the deadline if you can.
Step 3: transfer, never withdraw
If you want to move ISA money to a better rate, use the new provider's ISA transfer process. Withdrawing the money and paying it in yourself counts as a new subscription and uses your allowance, unless the original ISA is flexible and you replace the money in the same account within the same tax year.
Since April 2024 you can pay into more than one ISA of the same type in a tax year (except Lifetime ISAs), and partial transfers of money paid in during the current year are allowed. That gives you more flexibility, but transfers can take up to 15 working days for Cash ISAs, so start them early. Our ISA transfer guide covers the details.
Step 4: choose where the money goes
If you are short of time, you do not need to make every decision before 5 April.
- Easy-access Cash ISA: the simplest place to secure the allowance quickly. You can move it to a fixed rate later by transfer. Compare options in our savings and Cash ISA guide
- Stocks and Shares ISA: you can pay in before the deadline and choose investments afterwards. New rules from April 2027 are expected to charge tax on interest earned on cash held in Stocks and Shares ISAs, so check your provider's guidance if you plan to leave cash uninvested for long
- Lifetime ISA: if you are 18 to 39 and saving for a first home or retirement, paying in up to £4,000 earns a bonus of up to £1,000. Withdrawals for other reasons carry a 25% charge
- Junior ISA: the £9,000 per child limit also resets on 6 April
Step 5: use both partners' allowances and Bed and ISA
Each adult has their own £20,000 allowance. If one partner has savings outside an ISA and the other has unused allowance, giving money to a spouse or civil partner is free of tax and can shelter more savings.
If you hold shares or funds outside an ISA, a Bed and ISA lets you sell them and buy them back inside your ISA. Any gain on the sale counts for capital gains tax, but the first £3,000 of gains each tax year is tax-free, so doing it each year can move investments into the ISA gradually. Most investment platforms offer this as a single service.
The four types of adult ISA
Before you rush to open an account, it helps to understand your options.
Cash ISA. The simplest option: your money earns interest tax-free. Rates change often, so compare the current best easy access and fixed-rate Cash ISAs on MoneySavingExpert or Moneyfacts. From 6 April 2027, under-65s can pay up to £12,000 a year into Cash ISAs. Best for people who want no risk and access to their money.
Stocks and Shares ISA. Your money is invested in funds, shares or bonds. Returns are not guaranteed, but over the long term (5 years or more) investing has historically tended to beat cash. All gains and dividends are tax-free inside the wrapper. Best for people with a longer time horizon who are comfortable with some risk.
Lifetime ISA. If you are between 18 and 39, you can pay in up to £4,000 a year and get a 25% government bonus (up to £1,000 a year). You can only withdraw without a 25% charge to buy your first home (up to £450,000) or after age 60. Best for first-time buyers saving for a deposit, or young savers planning for later life.
Innovative Finance ISA. Holds peer-to-peer loans and some other investments, including eligible crypto exchange-traded notes since 6 April 2026. Higher risk, and not protected by the FSCS like cash deposits. Best for experienced investors who understand the risks.
ISA rules you need to know
- Split the allowance: you can spread £20,000 across ISA types, for example £10,000 in a Cash ISA, £6,000 in a Stocks and Shares ISA and £4,000 in a Lifetime ISA
- More than one of each type: since April 2024 you can pay into multiple ISAs of the same type in one tax year (but only one Lifetime ISA)
- Cash ISA limit from April 2027: under-65s will be able to put no more than £12,000 a year into Cash ISAs; the rest of the £20,000 can go into other ISA types. Those 65 and over keep a £20,000 cash limit
- Transfers do not use your allowance: moving an existing ISA to a new provider through an ISA transfer does not count as a new subscription
- The deadline is fixed: money must be in your ISA by 5 April. Some providers have earlier cut-offs, so do not leave it to the last day
What if you don't have £20,000?
Most people don't max out their ISA allowance, and that's perfectly fine. Here's how to make the most of whatever you can afford:
- £100–£500: Open a Cash ISA with an easy-access provider. You'll earn tax-free interest and establish the habit of saving in an ISA each year.
- £500–£5,000: Consider splitting between a Cash ISA (for short-term needs) and a Stocks and Shares ISA (for long-term growth). Many investment platforms have no minimum contribution.
- £5,000–£20,000: If you have spare cash sitting in a current account earning nothing, moving it into an ISA is an easy win. At 4% tax-free, £10,000 earns you £400 a year with no tax to pay.
The real cost of not using your allowance
Let's put some numbers to it. Say you have £10,000 sitting in a standard savings account earning 4% interest. As a basic-rate taxpayer (20%), you'd pay tax on interest above your £1,000 Personal Savings Allowance. As a higher-rate taxpayer (40%), your allowance drops to £500.
Inside an ISA, all that interest is tax-free. Over 10 years, the compounding tax savings can amount to thousands of pounds, money that stays in your pocket rather than going to HMRC.
What changes from April 2027
From 6 April 2027, the overall ISA allowance stays at £20,000 but under-65s can put only £12,000 of it into Cash ISAs; the rest must go into Stocks and Shares or Innovative Finance ISAs. People aged 65 and over keep the full £20,000 cash limit. Transfers from Stocks and Shares ISAs into Cash ISAs will also be restricted.
Money already in Cash ISAs is not affected. So if you are under 65 and want more of your savings in cash, the year ending 5 April 2027 is your last chance to add a full £20,000. Our guide to Cash ISA vs Stocks and Shares ISA explains how to split your allowance under the new rules.
Make next year less of a rush
The easiest way to use your allowance without a last-minute scramble is a monthly standing order into your ISA from the start of the tax year. £1,667 a month uses the full £20,000; smaller amounts still add up. Set a goal in our savings goal calculator and see the long-term effect with the compound interest calculator. If daily amounts suit you better, SYM can spread an ISA goal across the year.
Frequently asked questions
Quick answers to the questions people ask most as 5 April gets close.
What time is the ISA deadline on 5 April?
Can I open a new ISA on 5 April?
Does an ISA transfer use my allowance?
Can I pay into a Stocks and Shares ISA and invest later?
What happens to unused ISA allowance?
When is the ISA deadline for 2026/27?
How much can I put into an ISA this year?
Can I open an ISA in the last week before the deadline?
What happens if I exceed my £20,000 ISA allowance?
- ISA deadline
- ISA allowance
- tax year end
- tax-free savings
- UK finance