Every 5 April at midnight, the UK tax year ends. Any unused ISA allowance for that year vanishes — it cannot be carried forward. If you haven't used your £20,000 by the deadline, you lose the tax benefit on that money forever. Same applies to the £9,000 Junior ISA allowance and the £4,000 Lifetime ISA limit.
Here's how to make sure you don't miss it this year.
6-step ISA deadline checklist
Check how much allowance you have left
Log into your current ISA provider and check your contributions for this tax year. The number you need is £20,000 minus what you've already paid in across all adult ISAs combined (Cash + Stocks & Shares + LISA + IF ISA). If you've made zero contributions, you have the full £20,000 available.
Decide which wrapper to use
A Stocks & Shares ISA is the right answer for most UK investors with a 10+ year horizon. Cash ISA is safer for short-term goals (1–3 years). Lifetime ISA gets a 25% government bonus but is restricted to first-home or retirement use.
Pick a provider
For speed: Trading 212 can open and fund an ISA in under 10 minutes via debit card. Vanguard takes longer (needs direct debit setup). HL and AJ Bell accept debit-card top-ups but their cut-offs are earlier on deadline day. See our Platform Finder or top picks below.
Open the account and deposit the money
Use debit card for immediate funding if you're close to deadline. Bank transfers can take 1–2 working days. Set up the deposit for at least the amount you want to shelter — you don't have to invest it all at once, but it has to be in the ISA by 23:59 on 5 April to count as this year's allowance.
Invest (or leave as cash)
Money in a Stocks & Shares ISA can sit as cash indefinitely while you decide where to invest. The allowance is used up the moment the cash enters the ISA — you don't have to buy anything right away. If in doubt, a single global index fund like Vanguard FTSE Global All Cap or a global ETF is the common beginner choice.
Do it for the kids too
The Junior ISA deadline is the same day. £9,000 per child, tax-free, lost forever if you don't use it. See our Junior ISA comparison for providers that accept same-day card funding.
3 ISAs you can open today
Trading 212 ISA
Zero fees. Fastest to open. Debit card funding until late on deadline day. The lowest-friction ISA in the UK for anyone starting from scratch.
Open Trading 212 ISA →Affiliate. FCA authorised. Capital at risk.
Vanguard UK ISA
Best for the simplest long-term setup. 0.15% capped fee. One-fund LifeStrategy investing. Direct-debit setup means it's slower to fund same-day.
Visit Vanguard UK →Direct link — no affiliate. FCA authorised.
Hargreaves Lansdown ISA
Established UK broker with phone support. Frequent £75+ new-money cashback offers for ISA transfers. Check their current deadline cut-off before you start.
Open HL ISA →Affiliate. FCA authorised. Capital at risk.
Not sure which suits you? Take our 60-second Platform Finder → — answer 4 questions and we'll recommend one of these (or a better fit).
What counts toward this year's allowance?
The £20,000 limit applies to new money paid in during the tax year (6 April — 5 April). It does not include:
- ISA transfers from other providers (these don't use up any allowance)
- Reinvested dividends inside an existing ISA
- Capital growth of existing investments
- Interest on existing Cash ISA balances
So if you transferred a £50,000 ISA from one provider to another this year, you still have your full £20,000 contribution allowance available separately.
What you can (and cannot) do on 5 April
| Action | Deadline |
|---|---|
| Open a new ISA with a provider | Usually until 22:00–23:00, provider-specific |
| Fund via debit card | Varies — check your chosen provider's specific 5 April page |
| Fund via bank transfer | Usually too late on 5 April — use Faster Payments earlier in the week |
| Invest the cash (buy a fund/ETF) | Not required — cash inside ISA counts as using allowance |
| Transfer in from another ISA | Doesn't affect this year's allowance — can be done any time |
After the deadline: what happens at 6 April?
A fresh £20,000 adult ISA allowance (and £9,000 Junior ISA allowance) resets at 00:00 on 6 April for the new tax year. Anything you couldn't fit in this year's allowance can go straight into the new year's — but the previous year's unused allowance is gone.
If you have more than £20,000 to invest and you missed the deadline, your options are:
- Fund the new £20,000 allowance from 6 April
- Put the rest in a General Investment Account (GIA) and move it into ISAs across future tax years — "Bed and ISA" if you want to trigger CGT deliberately to use the £3,000 annual exempt amount
- Consider a SIPP for the tax-relief advantage on retirement money — see our Pension vs ISA guide
Frequently asked questions
When exactly is the UK ISA deadline?
23:59 on 5 April each year. This is the last moment to pay money into an ISA and have it count toward that tax year's £20,000 allowance.
Can I open an ISA on 5 April itself?
Yes, but most providers have same-day cut-off times earlier than midnight. Trading 212, Vanguard and InvestEngine typically accept same-day debit-card funding until late evening; HL and AJ Bell often cut off by 17:00. Check the specific provider.
What if I already have an ISA elsewhere?
You can open a second ISA with another provider this tax year (rules changed in April 2024). You just can't exceed £20,000 total across all of them. You can also transfer an existing ISA — transfers don't count toward the annual allowance.
Do I have to invest the money on 5 April?
No. The money just needs to be inside the ISA wrapper by the deadline. You can leave it as cash and decide later. Most ISAs pay some interest on uninvested cash.
Sources: gov.uk/individual-savings-accounts, MoneyHelper Stocks & Shares ISA guide. Tax treatment depends on individual circumstances and may change. Capital at risk.