The 90-Day ISA Cash Transfer Rule: How to Move Without Losing Your Allowance

Withdrawing money from your cash ISA to chase a better rate elsewhere is one of the most expensive mistakes a UK saver can make — and one of the most common. The moment cash leaves the ISA wrapper, you lose that portion of your annual allowance permanently. If you have already used your £20,000 ISA allowance for the year, you cannot put that money back into any ISA until the following tax year, and even then it counts against the new year's allowance.

The correct method — an ISA transfer — protects your allowance completely. This guide explains exactly how it works, how long it takes, what the rules say, and where people trip up. Whether you are moving a cash ISA, a Stocks and Shares ISA, or a Lifetime ISA, the process matters more than most providers make clear.

Why Withdrawing and Re-Depositing Destroys Your Allowance

An ISA (Individual Savings Account) allowance is use-it-or-lose-it per tax year. In 2026/27 you can contribute up to £20,000 across all ISAs. When you put money into an ISA, it is sheltered from income tax and capital gains tax for as long as it stays inside the wrapper.

When you withdraw from an ISA, the money leaves the wrapper. That portion of your allowance does not come back. A concrete example: you have a cash ISA with £15,000 in it, all contributed in previous tax years. You withdraw £15,000 to deposit in a new ISA offering a better rate. You now have no cash ISA balance, but that £15,000 withdrawal does not re-create £15,000 of fresh allowance. Your 2026/27 allowance is still only £20,000 in total across all ISAs. If you have already used £10,000 of this year's allowance, you can only contribute £10,000 more — meaning only £10,000 of that £15,000 can go back into any ISA this tax year. The remaining £5,000 sits in an ordinary savings account, taxable.

The only exception is a Flexible ISA — a specific type where the provider explicitly allows withdrawals and re-deposits within the same tax year without affecting allowance. Not all ISAs are flexible. Check your provider's terms before assuming.

The ISA Transfer Process: How It Works

An ISA transfer is a formal process — distinct from a withdrawal — whereby your money moves directly between providers while staying inside the ISA wrapper. Your allowance is fully preserved regardless of whether the money being transferred was contributed this tax year or fifteen years ago.

The process:

1. You open a new ISA with the receiving provider (or choose an existing one).
2. You complete a transfer authority form with the receiving provider — not the one you are leaving.
3. The receiving provider contacts the current (ceding) provider on your behalf.
4. The ceding provider closes or reduces your ISA and transfers the funds directly to the receiving provider.
5. The receiving provider confirms receipt and credits your account.

You do not handle the money at any point. This is the critical distinction.

Always initiate a transfer through the receiving provider. Do not contact your existing provider and ask them to close your account — that constitutes a withdrawal, not a transfer.

FCA Rule: 15 Business Days for Cash ISA Transfers

From 2024, the Financial Conduct Authority (FCA) introduced a binding rule requiring cash ISA transfers to complete within 15 business days of the transfer being authorised. This was a significant tightening: previously, the standard was set by industry practice rather than regulation, and 30-day or longer delays were common.

Fifteen business days equates to approximately three calendar weeks, excluding bank holidays. In practice, many digital providers now complete transfers within 7–10 business days.

The 15-day clock starts from the point the ceding provider receives a valid transfer request — not from when you initiate it with the receiving provider. Allow a day or two for the receiving provider to forward the request.

What Happens If a Provider Misses the Deadline

If your cash ISA transfer takes more than 15 business days after the request reaches the ceding provider, the FCA expects providers to have adequate systems to detect and correct failures. If your transfer is delayed:

1. Contact the receiving provider first — they can chase the ceding provider formally.
2. Write a formal complaint to the ceding provider — this triggers their 8-week deadline to resolve or issue a Final Response Letter.
3. Escalate to the Financial Ombudsman Service (FOS) — you can escalate after 8 weeks or if you receive a Final Response you disagree with. The FOS can award compensation for quantifiable loss (e.g., interest you missed at the higher rate during the delay) and a goodwill payment.
4. Reference the FCA rule directly in your complaint — mentioning COBS rules and the 15-day standard strengthens your position.

Keep records of the dates: when you submitted the transfer request, when you received confirmation it was sent to the ceding provider, and when funds were credited.

Stocks and Shares ISA Transfers: Expect 30+ Days

The 15-day rule applies to cash ISA transfers only. Stocks and Shares ISA transfers take longer — typically 30 to 60 days — and the FCA does not impose the same hard deadline because the transfer process is more complex.

There are two types of S&S ISA transfer:

Cash Transfer (Liquidating Transfer)

Your investments are sold, the proceeds converted to cash, and the cash is transferred to the receiving platform. Timeline: 30–45 days typically. You are out of the market during this period — if markets move significantly, this is your risk.

In-Specie Transfer

Your investments are transferred "as is" to the new platform without being sold. Not all platforms support in-specie transfers, and those that do require both platforms to hold compatible assets. Timeline: can be 6–12 weeks. Advantage: you stay invested throughout.

If speed matters — for example, if you are trying to move before the tax year end — a cash transfer is faster but carries market risk. For long-term investors who simply want to switch platforms, in-specie is usually worth the wait.

Partial Transfers

You do not have to transfer your entire ISA balance. Partial transfers are permitted under ISA regulations, subject to one important restriction: you can only partially transfer ISA funds contributed in previous tax years. Contributions made in the current tax year must be transferred in full or not at all.

Example: your cash ISA contains £8,000 contributed this tax year (2026/27) and £22,000 from previous years. You want to move £15,000 to a new provider. You can transfer all £22,000 from prior years (or any portion of it), but the current year's £8,000 must be moved in its entirety or left completely.

In practice, this rule is managed by the receiving provider's transfer form, which asks you to specify what portion you want to move. Most forms handle the current vs. prior year split automatically.

Lifetime ISA Transfers: The £50 Fee Warning

Transferring a Lifetime ISA (LISA) to a new provider is permitted but carries a specific risk: some LISA providers charge a transfer fee, historically up to £50. More importantly, LISA transfer options are limited because fewer providers offer LISAs compared to standard cash ISAs.

Current LISA providers (2026) include Moneybox, Beehive Money, Skipton Building Society, and Nutmeg (S&S LISA). Not all of these accept incoming LISA transfers — check before initiating.

The £25% government withdrawal penalty applies if you withdraw from a LISA for any purpose other than:

• Purchasing your first home (purchase price up to £450,000)
• Retirement (age 60+)
• Terminal illness

A LISA transfer to another LISA provider does not trigger the withdrawal penalty, because the money stays within the LISA wrapper. However, if your receiving provider does not accept the transfer, you face a choice between keeping the LISA with the current provider or withdrawing and paying the penalty. Check provider compatibility before initiating.

Platform Comparison: Rates and Transfer Times (2026)

Rates change frequently; always check directly with providers. The figures below were indicative in early 2026 and should be verified before making decisions.

Note: Trading 212's rate includes a loyalty bonus tier. Verify the specific product terms — headline rates may apply only to new money or for a limited period.

Step-by-Step: How to Transfer Your Cash ISA Correctly

1. Compare rates and confirm the receiving provider accepts transfers in. Not all ISA products accept transferred funds — some are only open to new subscriptions. Check the small print.
2. Open the new ISA with the receiving provider (if you don't already have one). You can often do this online in 10 minutes.
3. Request a transfer through the receiving provider's portal or app. You will need your current ISA provider's name, account number, and sort code.
4. Specify the transfer amount — full or partial, and whether to include current-year contributions.
5. Do not touch the existing ISA. Do not withdraw, do not change anything with your existing provider. Let the receiving provider manage the process.
6. Wait. You will receive confirmation from both the receiving and ceding provider. Cash ISAs: expect 7–15 business days. S&S ISAs: 30–60 days.
7. Check the interest/growth calculation. Confirm interest was paid up to the transfer date by the old provider and has started accruing at the new provider.
8. Keep your original provider's confirmation of the transfer — useful if there is ever a dispute about allowance usage.

Common Mistakes to Avoid

Closing your ISA before transferring. Closing creates a withdrawal. Even if you call it "moving," if the provider sends you a cheque or pays into your current account, it is a withdrawal.

Opening a new ISA and depositing fresh money while a transfer is in progress. This is fine from an allowance perspective — but make sure you know what you are adding versus what is being transferred, to avoid accidentally exceeding your £20,000 allowance.

Assuming flexible ISA rules apply everywhere. Flexible ISAs allow withdrawals and re-deposits within the same tax year. Standard ISAs do not. Your provider's terms will state which type you have. If in doubt, always transfer.

Not checking if the new provider's rate is for new money only. Some providers offer a high rate on fresh subscriptions but a lower rate on transferred balances. Read the product terms carefully.

Leaving it too late before the tax year end. If you want a transfer to count towards or protect your 2026/27 allowance usage, initiate it by mid-March at the latest. The 15-day deadline means a transfer initiated on 20 March could still be in progress on 5 April, which creates complications. Two weeks of buffer is sensible.

Use our compound interest calculator to model how much difference the interest rate gap makes over time — sometimes a 0.5% rate improvement on a £20,000 ISA makes a meaningful difference over 5 years.

Key Takeaways

• Never withdraw and re-deposit — the correct method is always an ISA transfer, initiated through the receiving provider.
• The FCA requires cash ISA transfers to complete within 15 business days from 2024; if your provider is late, you can claim compensation via the Financial Ombudsman Service.
• Stocks and Shares ISA transfers take 30–60 days; in-specie transfers keep you invested but take longer.
• Partial transfers are allowed on previous-year contributions only; current-year contributions must be moved in full or not at all.
• LISA transfers to a compatible provider do not trigger the 25% withdrawal penalty, but check your receiving provider accepts incoming LISA transfers before starting.