How to Move From a Cash ISA to a Stocks & Shares ISA in 2026 (Step by Step)

Moving money from a Cash ISA into a Stocks & Shares ISA is simple — but there's one step that catches people out, and it's expensive.

You never touch the money yourself. You open the new Stocks & Shares ISA, start an ISA transfer from inside it, and let the two providers move the cash between them. Do it that way and your tax-free wrapper survives and your £20,000 annual allowance is untouched. Withdraw it manually instead and you permanently lose the tax-free status on everything you moved.

Here's the full process as it works in 2026, what it costs, how long it takes — and why the April 2027 rule changes make this a decision worth thinking about properly rather than reversing later.

The 2027 change that makes this a one-way door

Most coverage of the ISA reforms focuses on the headline: from 6 April 2027 the Cash ISA allowance drops to £12,000 a year for under-65s, while the overall ISA allowance stays at £20,000. We covered that in detail in our guide to the Cash ISA allowance cut.

The part that matters for this decision is buried in HMRC's anti-circumvention factsheet, published 23 June 2026. From 6 April 2027:

• Transfers from a Stocks & Shares ISA back into a Cash ISA will not be permitted. Moving Cash ISA money into investments stays allowed. The reverse does not.
• A flat 22% charge applies to interest paid on cash held inside a Stocks & Shares ISA. Sitting in cash inside an investment ISA stops being a free parking space.
• A portfolio made up of 100% cash-like assets becomes non-qualifying. From April 2027, "cash-like" means money market funds only, and they can be a partial allocation but not the whole account.

Ordinary investments — shares, funds, investment trusts, ETFs, corporate bonds and gilts — are explicitly not treated as cash-like.

Two practical takeaways. First, if you're under 65 and thinking about moving cash into investments, the door is open now and open indefinitely in that direction — there's no deadline pressure. Second, if you're not sure the money should be invested at all, don't move it as a hedge. After April 2027 you can't quietly move it back.

(Those aged 65 and over keep the £20,000 cash limit and are exempt from the transfer restriction — but the 22% charge and the cash-like rule still apply to them.)

The rules are set to be finalised by regulations laid in autumn 2026, following a technical consultation, so details could shift before they take effect.

First: decide what shouldn't move

The tax rules are the boring part. This is the part that actually determines whether the transfer was a good idea.

Keep in cash: your emergency fund, and anything you expect to spend within roughly five years — a deposit, a wedding, a car, a career break. Investments fall as well as rise, and a five-year horizon is the rough point at which the odds start working in your favour rather than against you. There's no rule that says you must use your full allowance.

Consider investing: money you genuinely won't need for five years or more, where the risk of a bad decade is a risk you can sit through.

The 2027 changes reduce how much you can shelter in cash. They don't change what any particular pot of money is for. If your Cash ISA holds six months of expenses, it should still hold six months of expenses in April 2027.

Worth checking before you move anything: with a personal savings allowance of £1,000 for basic-rate taxpayers and £500 for higher-rate, some savers were never paying tax on their savings interest anyway. Our savings interest tax guide covers where those thresholds bite.

How to transfer, step by step

The whole process runs from the receiving end. You don't need to contact your Cash ISA provider at all.

1. Open the Stocks & Shares ISA first. It's free to open at every app we cover, and you can open it without funding it. You can only pay new money into one Stocks & Shares ISA per tax year — but transfers don't count as new money.

2. Find the transfer section, not the deposit section. In-app it's usually labelled "Transfer an ISA" or "Portfolio transfer". Depositing money you've withdrawn yourself is the mistake this whole article exists to prevent.

3. Give them your old provider's details. You'll need the provider name, your account or ISA number, and roughly how much you're moving. The new provider generates the paperwork and contacts your old one directly.

4. Choose full or partial. Money from previous tax years can be split in any amount — you can move £8,000 of a £20,000 Cash ISA and leave the rest earning interest. Money you've paid in during the current tax year is trickier: HMRC has allowed partial transfers of current-year subscriptions since April 2024, but ISA managers aren't required to offer them. If either side doesn't support it, your whole current-year contribution has to move together.

5. Wait. The industry guideline for a transfer into a Stocks & Shares ISA is up to 30 calendar days. Cash transfers often land in around two weeks. You'll usually see a status tracker in the new app.

6. Decide what to buy — and don't take forever. The money arrives as cash. There's no rule forcing you to invest it on day one, and drip-feeding it in over a few months is a perfectly reasonable way to handle the fear of buying at the top. But from April 2027, cash sitting in a Stocks & Shares ISA earns interest subject to a 22% charge, so "I'll decide later" gets a running cost. If you want a starting point, our beginner's guide to UK ETFs covers global trackers and the accumulating-versus-distributing question.

The mistakes that actually cost money

Withdrawing the money yourself. Pull £15,000 out of a Cash ISA and pay it into a Stocks & Shares ISA manually and two things happen: the historic tax-free status is gone for good, and the £15,000 deposit eats three-quarters of your current year's £20,000 allowance. Transfers avoid both.

Assuming a "flexible" Cash ISA protects you. A flexible ISA lets you withdraw and replace money in the same tax year without using allowance. It does not make a manual move to another provider safe — replacements have to go back into the same account. Use the transfer process regardless.

Forgetting about interest during the gap. Most Cash ISAs stop paying the moment the money leaves, and it may sit uninvested for a few days at the other end. On £10,000 over three weeks at around 3.75%, that's roughly £22. Small, but not nothing — and a reason not to start a transfer and then stall for a month.

Losing a promotional rate you didn't realise you had. Bonus rates on Cash ISAs are usually paid for a fixed window on money contributed in a specific tax year. Moving early can end that early. Check what you're giving up before you start.

Moving to a Cash ISA "for now" with the intention of investing later. From April 2027 that route closes in one direction only. Plan the destination once.

Where to open the Stocks & Shares ISA

All three below are FCA-authorised, accept inbound ISA transfers, and charge nothing to transfer in or out. Figures are as of 21 July 2026 — with the Bank of England base rate at 3.75%, held at the 17 June 2026 MPC meeting — and rates move, so confirm on the provider's own site before you commit.

One honest note, since it cuts against the obvious pick: on the numbers above, Lightyear's Cash ISA rate (3.75%) is currently higher than Trading 212's standard rate (3.60%), though Trading 212's promotional rates for new customers can reverse that. If you're keeping a cash pot alongside your investments, compare both — we go through the differences in our Trading 212 vs Lightyear comparison. If you'd rather see the wider field first, start with our best investing apps UK roundup or the three-way comparison.

FAQ

Can I transfer a Cash ISA to a Stocks and Shares ISA? Yes, and HMRC's 2027 reform documents confirm this direction remains permitted. Use the official transfer process, started from the new provider.

Does transferring use up my £20,000 allowance? No. Previous years' money transfers across without touching your current-year allowance. Only new contributions count.

How long does it take? Up to 30 calendar days is the guideline for transfers into a Stocks & Shares ISA; cash often moves in around two weeks. Moving existing investments in-specie takes longer, commonly four to eight weeks.

Can I move just part of it? Previous years' money, yes — any amount, split however you like. Current-year money depends on whether both providers support partial transfers of current-year subscriptions.

Can I change my mind afterwards? Until 5 April 2027, yes — you can transfer back to a Cash ISA. From 6 April 2027 that route closes for under-65s.

Should I move my emergency fund? No. Short-term money belongs in cash whatever the allowance rules say.

This is general information, not financial advice. Figures are correct as of 21 July 2026 and change frequently — check the provider's own site before acting. The April 2027 ISA rules are as set out in HMRC's factsheet of 23 June 2026 and remain subject to consultation and final regulations. Do your own research and consider speaking to a qualified adviser about your situation.

Last updated: 21 July 2026.