What happens when a fixed rate ISA matures?

What does it mean when a fixed rate ISA matures?

A fixed rate Cash ISA pays a guaranteed rate for a set term, commonly 1, 2, 3 or 5 years, in return for leaving the money untouched for that time. Maturity is the end of that term. The rate was only ever promised for the fixed period, so once it ends the lock comes off and the money is yours to do something with.

What maturity does not do is end the tax shelter. gov.uk says you do not pay tax on interest on cash in an ISA, and that stays true for as long as the money remains inside an ISA. So a maturing fix is not a deadline to rescue your savings from tax; it is a prompt to decide where the balance should sit next, because the rate you were getting is about to change.

The interest you earned over the term also belongs to you, tax-free, and it does not use up any of your ISA allowance. Interest on money already inside an ISA is not a new subscription, so the balance can grow well beyond the annual limit without any consequence for what you can pay in.

What are your options when a fixed rate ISA matures?

There are four, and they are the same across almost every provider even though the labels differ.

The first two keep both your money and its tax-free status working. Withdrawing keeps the cash but gives up the wrapper on whatever you take out, which matters because you cannot simply pay it back in without using fresh allowance. Doing nothing is the default, and it is the one most likely to cost you quietly, because the account the money lands in is rarely the best rate on the market.

What notice will your provider give you before maturity?

You should not be caught out by the date, because firms are expected to tell you it is coming.

The FCA’s Banking: Conduct of Business Sourcebook sets this out in BCOBS 4.1. The guidance at BCOBS 4.1.2(6A)G says a firm should give notice “in good time before the end of the fixed term”, explaining the consequences of the term ending and the options for dealing with the balance. Where that notice is sent more than 14 days ahead, BCOBS 4.1.2(6B)G says the firm should also send a reminder within the 14 days before the change takes effect. In practice providers tend to write a few weeks before maturity and then again as the date nears.

These are items of guidance rather than hard rules, so the exact timing varies between providers. If you want to know the precise cut-off for giving instructions, the clearest place to look is the account’s own summary box. Under BCOBS 2 Annex 1, the summary box for a fixed-term account must answer “Can I withdraw money?” and, for fixed-term products, include “an explanation of what happens at the end of the fixed term”. That tells you the provider’s default and the deadline for telling them to do something else.

What is a maturity or default account, and why does it matter?

If you give no instructions, the provider needs somewhere to put the money, so most move it into a default maturity account. This is typically an easy access Cash ISA. The balance stays inside the ISA and stays tax-free, but the rate is set by the provider and is often well below what a new fixed or easy access deal pays.

This is where doing nothing has a price. Consider a worked illustration, using round numbers that are examples only and are not the rate on any account: suppose £10,000 matures and rolls into a default account paying 1.5% AER, while a new one-year fix elsewhere pays 4% AER. Over a year, the default account earns about £150 and the fix earns about £400. The gap, roughly £250 on £10,000, is the cost of letting the money sit where it landed. Scale that to your own balance and the real rates in our tables to see what a decision is worth.

Because the money is still inside an ISA, there is no rush and no tax cost to moving it later. But the longer it sits in a low-paying default account, the more interest you forgo. Compare the current easy access Cash ISA rates and fixed rate ISA rates before deciding, rather than leaving the provider’s default to decide for you.

How do you move a matured ISA to a new provider without losing the allowance?

If you want a better rate elsewhere, use an ISA transfer. Apply to the new provider and ask them to arrange the move with your old one; do not withdraw the cash and pay it in yourself.

The reason is strict. gov.uk says that if you withdraw the money without using the transfer process, “you will not be able to reinvest that part of your tax-free allowance again”. A transfer keeps the wrapper intact; a withdrawal does not. gov.uk says transfers between Cash ISAs should take no longer than 15 working days, and other types within 30 calendar days, whether the money was paid in this year or in an earlier year.

HMRC’s guidance for ISA managers explains how the 15 business days are counted: the new manager has 5 business days to send the instruction to the old one, the old manager has 5 business days to send the money and information, the new manager has 3 business days to apply it, and 2 further days cover first-class post. One timing point matters at maturity: if you send a transfer instruction and later change it after the term has ended, HMRC says the revised instruction “will be treated as a new transfer instruction that initiates a fresh timetable”, so the clock starts again. Our ISA transfer guide walks through the full process.

Does re-fixing count as a transfer or a new subscription?

No, and this is a common worry that the rules settle clearly.

HMRC’s guidance for ISA managers says that “a transfer application is not required where an existing ISA investment is switched from one product to another (which is what happens on the maturity and ‘roll-over’ of a fixed-term product)”. In other words, moving your maturing balance into a new fix with the same provider is an internal switch, not a transfer. It is also not a new subscription, because the money is already inside the ISA, so it does not use any of your annual allowance.

Where you move to a different type of ISA, HMRC says a transfer application is required, so a switch from a Cash ISA to a Stocks and Shares ISA, for example, goes through the transfer route. For a straightforward re-fix of cash into cash, the paperwork is minimal and your allowance is untouched. If you also want to add brand new money to the new fix, that new money is a subscription and counts towards your allowance in the usual way.

Does the April 2027 Cash ISA limit change what happens at maturity?

No. HMRC had planned a £12,000 Cash ISA limit from 6 April 2027 for savers under 65, but the Budget on 28 October 2026 cancelled it, so the limit stays £20,000. Even under that plan the limit applied to subscriptions, meaning new money paid in during a tax year, so a balance already sitting in a Cash ISA that matures and rolls over, or that you transfer to another Cash ISA, would not have counted against it. Nothing about a maturing fix changes. See the Cash ISA limit.

At a glance

Options at maturity

4

Re-fix, transfer, withdraw, or do nothing

Cash ISA transfer time

15 working days

gov.uk, Cash ISA to Cash ISA

Reminder before the term ends

Within 14 days

FCA guidance, if the first notice went out earlier

Cash ISA limit from 6 April 2027

£20,000

Planned cut to £12,000 cancelled

For the decision of whether to re-fix at all, or to keep the money easy access instead, see should I fix my ISA, or stay easy access. For how rates move with the Bank of England, see will Cash ISA rates go up or down.