Transferring an ISA the right way — the rule that protects your allowance

Moving an ISA from one provider to another sounds like it should be the same as moving any other account — withdraw, deposit, done. It isn’t. Do that with an ISA and you usually wipe out the tax-free status of every penny you move. The official ISA transfer process exists precisely so you don’t.

This is how transfers actually work, what to watch for, and the few rules that catch people out.

Why “just withdraw and redeposit” doesn’t work

The £20,000 annual ISA allowance limits how much new money you can put in across all your ISAs in a tax year. Money already inside an ISA — from this year or any previous year — sits outside that limit and grows tax-free indefinitely. The moment that money leaves the wrapper, it becomes ordinary cash. Paying it into a new ISA counts as a fresh subscription, and uses up your current-year allowance.

So if you have £40,000 sitting in an old cash ISA and you withdraw it, then pay it into a new ISA, two things happen:

1. You blow through your £20,000 allowance, and the remaining £20,000 just won’t fit. It has to sit in a taxable account.
2. Even the £20,000 you do get back in is now this year’s subscription — you can’t add anything else this year.

An official transfer, by contrast, moves the money provider-to-provider without it ever leaving the ISA wrapper. The whole balance keeps its tax-free status, and none of it counts against this year’s £20,000 allowance.

How to do it properly

The mechanic is:

1. Open the new ISA with the receiving provider (or identify an existing one you want to transfer into).
2. Fill in the receiving provider’s transfer form, giving them your old account details. Most providers have an online form these days.
3. They contact your old provider and request the funds. You don’t touch the cash yourself.
4. The money moves within the timescales the HMRC framework sets (15 working days for cash ISA to cash ISA, 30 calendar days for everything else).

The key word on the form is “transfer” — not “new subscription”. If you pay money into the new ISA from your current account first, then later try to add the old ISA balance, that’s a new subscription, not a transfer, and the wrapper protection is gone.

HMRC’s guidance for ISA managers describes the process from the provider side; the practical version most savers care about is on MoneyHelper.

The current-year rule that catches people out

There’s one constraint people regularly miss: money paid into an ISA in the current tax year must be transferred as a single block. You can’t split this year’s £12,000 of contributions across two new ISAs of the same type.

Previous-year money is more flexible — you can split that across as many receiving ISAs as you like, in any amounts.

So if you’ve paid £15,000 into your current cash ISA so far this year, and you want to move some of it to a higher-rate provider, the choices are:

• Transfer the whole £15,000 of this-year money in one block, or
• Leave it where it is and transfer only the previous-year balance.

You can’t transfer £8,000 of this year’s subscription one way and £7,000 another. This is a frequent source of frustration when chasing the best rate mid-year.

Partial vs full transfers

Most providers accept partial transfers of previous-year ISA money. You can move £30,000 out of an £80,000 cash ISA and leave £50,000 behind — both halves stay sheltered.

A few providers, particularly fixed-rate ISAs or some older platform accounts, only accept full transfers. If you try a partial transfer on one of these, the request will be rejected, and you’ll have to choose between moving the lot or moving nothing.

Always check the receiving provider’s policy on partial transfers before starting — it’s the single thing that delays transfers most often.

Transfers between ISA types

You’re not stuck transferring like-for-like. Common cross-type transfers:

• Cash ISA → Stocks & Shares ISA. The money comes out as cash, and the receiving provider then invests it according to your instructions. Same wrapper, different exposure.
• Stocks & Shares ISA → Cash ISA. The shares are usually sold by the sending provider, with the cash proceeds transferred. Some providers offer in-specie transfer for stocks-to-stocks moves, where the actual holdings move across without being sold — but cash-out is the default.
• LISA → another LISA. Fine, no penalty, the bonus stays attached.
• LISA → non-LISA ISA. Counts as a withdrawal and triggers the 25% LISA withdrawal penalty unless it’s a qualifying first-home purchase or you’re over 60. Almost never worth doing voluntarily.
• Cash or S&S ISA → LISA. You can transfer existing ISA money into a LISA, but the amount transferred counts towards the LISA’s £4,000 annual contribution cap, and you have to be under 40 to open the LISA in the first place.

The general rule: cross-type moves are allowed, but the receiving wrapper’s rules govern what happens once it lands.

How long it actually takes

Statutory timescales are:

• Cash ISA to cash ISA: 15 working days.
• Anything involving Stocks & Shares: 30 calendar days.

In practice, transfers regularly take longer when the sending provider drags. You don’t lose interest or growth on the money in the meantime — providers are required to backdate either the closing or the opening interest so you’re not penalised by their delay — but the cash is in limbo and out of your control.

If a transfer takes more than the statutory window, contact both providers. If they don’t resolve it, the Financial Ombudsman Service handles ISA transfer complaints.

When transfers cost you money

A few situations where transferring isn’t free:

1. Fixed-rate ISAs in their fixed period. Withdrawing or transferring out almost always triggers an early-access penalty — typically 90–365 days of interest depending on the term. Sometimes worth paying if the new rate is dramatically better, but always check the maths first.
2. Stocks & Shares ISAs with exit fees. Most modern platforms have abolished exit fees, but a handful still charge per-holding fees for in-specie transfers out. Check before initiating.
3. Selling out of the market. A Stocks & Shares ISA cash-out transfer means your investments are sold and you’re out of the market for the transfer window. If markets move sharply during those 30 days, you’ve missed out. In-specie transfers avoid this.

Common mistakes

Three things to avoid:

1. Withdrawing instead of transferring. The most expensive mistake — covered above. Always use the receiving provider’s transfer form.
2. Splitting current-year money. You can’t transfer half of this year’s subscription one way and half another. Move the whole block or none of it.
3. Closing the old account before the transfer completes. The transfer process needs the old account to stay open. Closing it yourself can leave the money in limbo.

The transferring-ISA process is a piece of admin, not a financial decision. The decision is whether the new provider’s rate or features are worth the few weeks of delay. The transfer itself is just the right mechanic to get there without losing tax protection.

For the related rule on withdrawing and replacing within a single tax year (different mechanic, different purpose), see our guide to flexible ISAs.

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Last updated 1 June 2026. This guide is educational and is not personal financial advice. Transfer rules sit inside the HMRC ISA framework but providers have discretion over partial transfers, exit fees and in-specie support — verify your specific accounts before initiating. See our disclaimer.