Cash ISA Transfers: How to Move Your Money Without Losing a Penny of Tax-Free Status

This is the single most important thing to understand about ISA transfers, and it bears repeating: if you withdraw money from a cash ISA and deposit it into another, you lose your tax-free status on that money permanently. There is no way to reverse this.

The correct process uses an official ISA transfer form provided by your new provider. You fill it in, the new provider contacts your old one, and the money moves directly between institutions without ever landing in your bank account. Your tax-free wrapper stays intact throughout.

Here is what the two approaches look like in practice:

• The right way: Complete a transfer form with your new provider. They handle everything. Your ISA status is preserved. Cost: £0.
• The wrong way: Log into your old ISA, withdraw the cash, open a new ISA, deposit. Your previous years' contributions lose their tax-free status forever. The money you deposit counts against your current £20,000 annual allowance.

According to gov.uk guidance, you have the legal right to transfer your ISA to another provider at any time. Your existing provider cannot refuse a valid transfer request, though they may apply an early closure penalty on fixed-rate products.

The rules differ depending on whether you are transferring money paid in during the current tax year (2025/26) or money from previous years. Getting this wrong can create complications, so here is the breakdown.

Current tax year contributions (2025/26)

If you have paid into a cash ISA this tax year and want to transfer it, you must transfer the entire balance of current-year contributions. You cannot do a partial transfer of this year's money. This rule exists to prevent people from effectively splitting their subscription across multiple providers of the same ISA type within a single tax year, which ISA regulations do not allow.

Previous tax year contributions

Money from earlier tax years is more flexible. You can transfer all of it or just a portion — the choice is yours. This means if you have £30,000 built up across several previous years in one ISA, you could transfer £15,000 to a new provider and leave the rest where it is.

This flexibility matters if your current provider offers a decent rate on some products but not others, or if you want to spread your holdings across different institutions for FSCS protection (£85,000 per banking group).

Combining current and previous years

You can transfer current-year and previous-year money to different providers if you wish. The only constraint is that current-year money must move as a complete block.

ISA transfers have regulated maximum timescales, set by HMRC and enforced by the FCA. Your old provider must complete the transfer within these windows once they receive a valid request:

• Cash ISA to cash ISA: 15 working days (roughly 3 calendar weeks)
• Cash ISA to stocks and shares ISA: 30 calendar days
• Any other ISA transfers: 30 calendar days

In practice, many providers complete cash-to-cash transfers faster — some manage it in 5 to 7 working days. But you should always plan around the 15-working-day maximum, particularly if you are transferring close to the 5 April deadline.

What happens during the transfer window?

Your money typically earns no interest during the transfer itself. Some providers pay interest right up to the closure date and then the new provider starts paying from the date funds arrive, but there can be a gap of a few days. On a £20,000 balance at 4.68%, each lost day costs roughly £2.56 — noticeable but not catastrophic. The rate improvement from transferring almost always dwarfs any brief interest gap.

If your provider misses the deadline

If a transfer takes longer than the regulated timeframe, you have grounds to complain. Start with the provider's own complaints process. If that does not resolve matters, contact the Financial Ombudsman Service on 0800 023 4567 (free from landlines) or 0300 123 9123 (from mobiles). The Ombudsman can order providers to pay compensation for lost interest.

With the Bank of England base rate at 3.75% following the December 2025 cut, cash ISA rates vary significantly between providers. The best easy access cash ISAs pay up to 4.68%, while some older accounts languish below 2%. That gap compounds meaningfully over time.

Here is what a £20,000 ISA balance earns over one year at different rates:

The difference between a neglected 2% ISA and the best available rate is £536 per year on just £20,000. Scale that up to a larger ISA portfolio built over several years, and the numbers become substantial. Someone with £60,000 across old ISAs at poor rates could reclaim over £1,600 annually — tax-free — just by filling in a transfer form.

Fixed-rate cash ISAs currently offer around 4.21% for a one-year fix and up to 4.32% for longer terms. Whether fixed or easy access suits you better depends on your view of where rates are heading and whether you might need the money. With the Bank of England expected to continue its easing cycle, locking in now could prove wise — but easy access gives you the flexibility to switch again if something better appears.

For more on how to divide your ISA allowance effectively this tax year, see our guide to splitting your £20,000 allowance.

The process is straightforward. Here is exactly what to do:

1. Choose your new provider

Compare cash ISA rates and decide whether you want easy access or a fixed term. Check that the new provider accepts ISA transfers — most do, but a few newer accounts do not. Also confirm they accept transfers from previous years, not just current-year subscriptions.

2. Open the new ISA and request a transfer

You start the process with the new provider, not the old one. Apply to open a cash ISA and indicate that you want to transfer an existing ISA. They will provide a transfer authority form (sometimes called a transfer request form) — increasingly this is done online during the application.

3. Specify what you are transferring

Decide whether to transfer your full ISA balance or a partial amount. Remember: current tax year contributions must be transferred in full, but previous years can be split. Specify the amount or tick "full transfer" as appropriate.

4. Wait for the transfer to complete

Your new provider contacts your old one and arranges the transfer. You do not need to do anything with your old provider. The cash-to-cash transfer must complete within 15 working days. You should receive confirmation from your new provider once the funds arrive.

5. Verify the transfer

Check that the correct amount has arrived in your new ISA, including any interest owed up to the transfer date. Confirm that your old account is closed (if you did a full transfer) or reflects the correct reduced balance (if partial).

Important: do not close your old ISA yourself before or during the transfer. The transfer process handles this automatically for full transfers. Manually closing the account could be treated as a withdrawal, which destroys your tax-free status.

For a full overview of ISA rules and types, MoneyHelper's cash ISA guide provides a useful independent reference.

With the 2025/26 tax year ending on 5 April 2026, timing matters. Here are the key considerations:

Transferring existing ISAs does not use your annual allowance. Moving old ISA money from one provider to another is completely separate from the £20,000 subscription limit. You could transfer £100,000 of accumulated ISA savings and still have your full £20,000 allowance for new contributions.

But new contributions are time-sensitive. If you want to use your 2025/26 ISA allowance, you need the money in an ISA by 5 April. Given the 15-working-day transfer window, starting a transfer now and hoping it carries your new contribution in time is risky. The safer approach: make your new contribution directly to the ISA you want to use this year, then arrange transfers of older money separately.

Consider transfer timing carefully. If you initiate a transfer in late March and it spans the tax year boundary, your provider should handle the accounting correctly — but it introduces complexity. Where possible, complete transfers well before or well after 5 April to keep things clean.

Check our complete ISA deadline checklist for everything you need to do before 5 April.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions.