The Santander 1 Year Fixed Rate ISA currently pays 4.45% AER tax-free and is fixed until 1 October 2027. UK residents aged 18 or over can open the account with at least £500, while deposits can currently be made until 31 October 2026.
The account may appeal to savers who want to lock in a fixed interest rate while keeping their interest free from UK Income Tax. However, access is restricted.
If you want to take money out before maturity, Santander generally requires you to close or transfer the account and charges the equivalent of 120 days’ interest.
Santander states that its current Fixed Rate ISA rates and information were correct as at 3 September 2026 and that products may be withdrawn without notice.
Santander 1 Year Fixed Rate ISA: Quick Answer
Here are the main details of the Santander 1 Year Fixed Rate ISA for UK savers in 2026.
| Feature | Current Santander 1 Year Fixed Rate ISA |
| Interest Rate | 4.45% AER tax-free |
| Rate Type | Fixed |
| Fixed Until | 1 October 2027 |
| Minimum Opening Amount | £500 |
| Maximum Balance | £2,000,000, subject to ISA subscription limits |
| Deposit Deadline | 31 October 2026 |
| Interest Calculation | Daily |
| Interest Payment | Annually and at the end of the term |
| Early Access | Full closure or transfer only |
| Early Closure Charge | Equivalent to 120 days’ interest |
| Cancellation Period | 14 days |
| Eligibility | UK resident aged 18 or over |
Santander says the 4.45% AER calculation assumes funds are deposited by 1 October 2026. Paying money into the account earlier or later can mean the actual amount of interest earned differs from the headline AER illustration.
What Is The Santander 1 Year Fixed Rate ISA?
The Santander 1 Year Fixed Rate ISA is a fixed-rate Cash ISA designed for people who are prepared to leave their savings largely untouched until the fixed term ends.
An ISA, or Individual Savings Account, allows eligible UK savers to earn interest without paying Income Tax on that interest. Money held inside a Cash ISA also does not use up the saver’s Personal Savings Allowance.
With a fixed Cash ISA, the interest rate does not move during the agreed term. This gives savers certainty over the rate they will receive, but usually comes with tighter withdrawal rules than an easy-access Cash ISA.
For Santander’s current one-year product, the rate is fixed until 1 October 2027. Santander confirms that it cannot change the interest rate during the fixed term.
How Long Is The Santander Fixed Rate ISA Term?
The current Santander one-year ISA has a maturity date of 1 October 2027.
The advertised 4.45% AER assumes the money is deposited by 1 October 2026.
Santander allows qualifying deposits until 31 October 2026, which means someone funding the account later may have their money invested for less than a full year before maturity.
This is why savers should look at both the headline AER and the actual maturity date when considering a fixed-rate ISA.
Is The Interest Tax-Free?
Yes. Interest earned within an eligible Santander Cash ISA is tax-free under current ISA rules.
This means the interest does not count towards your Personal Savings Allowance. Tax rules can change, however, and the benefits of an ISA depend on individual circumstances.
What Is The Santander 1 Year Fixed Rate ISA Interest Rate In 2026?
The current Santander 1 Year Fixed Rate ISA rate is 4.45% AER tax-free.
AER stands for Annual Equivalent Rate. It is designed to show what the interest rate would produce over a year when interest payments and compounding are taken into account.
Santander calculates interest on the account each day. Interest is paid into the account annually and again when the fixed term ends.
Is the 4.45% Rate Fixed?
Yes. Santander states that the interest rate is fixed during the account term.
That does not mean Santander must continue offering 4.45% to new customers.
Fixed savings rates can change for new applicants, and Santander says its Fixed Rate ISA products are subject to availability and may be withdrawn without notice.
Anyone considering opening an account should therefore check the current rate before applying.
When Is Interest Paid?
Santander calculates interest daily and pays it into the account once a year and at the end of the term.
The interest becomes available the following day.
How Much Interest Could You Earn With The Santander 1 Year Fixed Rate ISA?
At an annual rate of 4.45%, the amount earned depends mainly on how much you deposit and when the money reaches the account.
The examples below show the approximate interest that different balances could earn if they received a full year at 4.45%.
| Deposit | Approximate Interest At 4.45% | Approximate Balance |
| £1,000 | £44.50 | £1,044.50 |
| £5,000 | £222.50 | £5,222.50 |
| £10,000 | £445.00 | £10,445.00 |
| £20,000 | £890.00 | £20,890.00 |
Santander’s own illustration confirms that a £1,000 deposit made on 1 October 2026 would earn £44.50, producing an estimated balance of £1,044.50 at the end of the one-year term.
The other figures above are simple illustrations based on 4.45%. Actual interest may differ if the money is deposited before or after 1 October 2026 or if other account circumstances affect the calculation.
Who Can Open A Santander 1 Year Fixed Rate ISA?
To qualify for the current Santander fixed Cash ISA, you generally need to meet the following conditions:
- Age Requirement: You must be aged 18 or over
- Residency Requirement: You must be a UK resident
- Account Ownership: The account must be held in your sole name
- Minimum Balance: You normally need at least £500
- ISA Rules: Your deposits must comply with the applicable annual ISA subscription rules
Joint Cash ISAs are not permitted.
Santander also allows the account to be opened with a zero balance when an existing ISA worth at least £500 is being transferred into it.
How Do You Open And Fund The Santander Fixed Rate ISA?
The Santander 1 Year Fixed Rate ISA can currently be opened in branch, through Santander’s mobile service or online.
Once opened, the minimum balance is £500 unless you are transferring an eligible existing ISA with a balance of at least £500.
Under the current product terms, new deposits can be made until 31 October 2026. After that date, Santander says it will not accept further deposits into this issue of the Fixed Rate ISA.
Money can currently be paid in electronically, in cash at a branch, by telephone or through Online Banking.
It is important to distinguish the account’s maximum balance from the ISA allowance. Santander lists a maximum account balance of £2 million, but new ISA subscriptions remain subject to the government’s annual ISA limits.
Can You Transfer An Existing ISA To Santander?
Yes. Santander currently accepts transfers from qualifying existing Santander Cash ISAs and ISAs held with other providers.
Using the formal ISA transfer process is important because withdrawing the money yourself before moving it could affect its tax-free ISA status.
For an ISA being transferred from another provider, Santander says:
- Transfer Request: Santander must receive the transfer application within 14 days of opening the account
- Transfer Completion: The transferred money must reach Santander within 30 days of opening
- Current-Year Subscriptions: Santander requires current tax-year ISA subscriptions to be transferred in full
- Previous-Year Savings: Some or all previous tax-year ISA funds can generally be transferred
A transfer from another ISA does not automatically use up the current year’s ISA subscription allowance simply because the existing ISA funds have moved between providers.
Can You Withdraw Money Early From The Santander Fixed Rate ISA?
You can access the money before maturity, but the Santander 1 Year Fixed Rate ISA is not designed as an easy-access account.
Santander says customers can withdraw all, but not part, of the ISA balance by closing the account or transferring the ISA to another provider.
If this happens outside the cancellation period, Santander charges a fee equal to 120 days’ interest.
What Is The 120-Day Interest Charge?
The 120-day interest charge is Santander’s early-closure cost.
The exact monetary amount will depend on the balance, interest rate and circumstances at the time of closure. This restriction is worth considering before locking away money that may be needed for emergencies or short-term expenses.
The account is also described as a non-flexible ISA. If money is withdrawn rather than transferred correctly and later paid into an ISA again, that new payment may count towards the applicable ISA allowance.
What Is The 14-Day Cancellation Period?
Santander provides a 14-day cancellation period, starting the day after it confirms that the account has been opened.
If the account is cancelled during this period, Santander says it will not apply the 120-day interest charge. It will return the money together with any interest due.
Different considerations can apply if money has already been transferred from another ISA provider.
What Happens When The Santander Fixed Rate ISA Matures?
The Santander 1 Year Fixed Rate ISA currently matures on 1 October 2027.
Santander allows customers to choose what they want to do with their Cash ISA money up to 28 days before the term ends.
Possible options may include moving to another Santander ISA, transferring to another ISA provider or choosing another available savings arrangement.
If no instruction is given, Santander currently says the maturing Fixed Rate ISA will be transferred to its ISA Saver account. The bank will provide details of the applicable interest rate closer to maturity.
Checking the available rates before maturity can be useful because the best option in October 2027 may be different from the products available in September 2026.
What Is The Cash ISA Allowance For 2026/27?
For the 2026/27 tax year, the overall annual ISA subscription allowance remains £20,000.
The tax year runs from 6 April to 5 April.
The £20,000 allowance applies across the ISAs you subscribe to rather than providing a separate £20,000 allowance for every ISA account. GOV.UK confirms that £20,000 is the maximum that can currently be subscribed to ISAs during the 2026/27 tax year.
How Is The Cash ISA Allowance Changing From April 2027?
A significant change takes effect on 6 April 2027.
HMRC confirmed on 17 September 2026 that the annual Cash ISA subscription limit will fall to £12,000 for people aged under 65.
For people aged 65 or over, the Cash ISA limit will remain £20,000.
The overall ISA subscription limit will remain £20,000.
This distinction is particularly important for anyone reading about Santander ISA rates in 2026.
The £12,000 Cash ISA limit is a future rule from 6 April 2027, not the Cash ISA limit applying during the current 2026/27 tax year.
Is Money In A Santander Cash ISA Protected By The FSCS?
Eligible deposits with UK-authorised banks are covered by the Financial Services Compensation Scheme, subject to its rules and limits.
The standard FSCS deposit protection limit increased from £85,000 to £120,000 per eligible person, per authorised firm on 1 December 2025.
This protection normally applies to the total eligible deposits held with the same authorised firm, rather than providing a separate £120,000 protection limit for each individual account.
That means someone holding several eligible savings accounts under the same banking licence should consider their combined balance when checking FSCS protection.
How Does The Santander 1 Year Fixed Rate ISA Compare With Other Cash ISAs?
Santander’s 4.45% fixed rate should be considered alongside the wider Cash ISA market rather than viewed in isolation.
The highest rate is not always the only factor worth considering.
Savers may also want to compare:
- Interest Rate: Compare the AER available when you are ready to open the account
- Minimum Deposit: Check whether the opening requirement fits your savings amount
- Access Rules: Consider how costly or difficult early access would be
- Transfer Rules: Check whether existing ISA money can be transferred
- Funding Deadline: Look at how long you have to add money
- Maturity Options: Check what happens when the fixed period ends
- Protection: Confirm the provider’s regulatory and FSCS position
A slightly higher interest rate elsewhere may be attractive, but account access, transfer restrictions and funding deadlines can also affect whether a product suits a particular savings plan.
Fixed Cash ISA rates can change frequently, so a rate described as competitive today may not remain so throughout 2026.
Santander 1 Year Fixed Rate ISA: Pros And Cons
The Santander fixed Cash ISA combines a guaranteed rate with tax-free interest, but the early-access restrictions mean it will not suit every saver.
Advantages
- Fixed Interest Rate: The rate does not change during the fixed term
- Tax-Free Interest: Eligible interest is earned within the ISA tax wrapper
- £500 Minimum: The opening requirement is lower than some high-balance fixed savings products
- ISA Transfers: Existing eligible ISA funds can be transferred
- Rate Certainty: Savers know the interest rate in advance
- FSCS Protection: Eligible deposits are protected within applicable FSCS limits
Things To Consider
- Restricted Access: Partial withdrawals are not available under the current terms
- Early Closure Charge: Closing or transferring early can cost 120 days’ interest
- Fixed Maturity Date: The account currently ends on 1 October 2027
- Funding Deadline: Deposits are currently accepted only until 31 October 2026
- Changing Market Rates: Other Cash ISA rates may rise or fall while your money is fixed
- Future ISA Rules: The Cash ISA subscription limit changes for under-65s from April 2027
Conclusion
The Santander 1 Year Fixed Rate ISA currently offers 4.45% AER tax-free, with the rate fixed until 1 October 2027.
It requires a minimum opening balance of £500 and provides certainty for savers who are comfortable leaving their money in place for the fixed term.
The main restriction is early access. Santander allows the full balance to be withdrawn or transferred before maturity, but a charge equivalent to 120 days’ interest generally applies outside the 14-day cancellation period.
Savers should also be aware of the 31 October 2026 funding deadline and the upcoming Cash ISA changes from April 2027.
As fixed ISA rates and product availability can change, checking Santander’s latest terms and comparing current Cash ISA options before opening an account remains important.
Frequently Asked Questions
What Is The Santander 1 Year Fixed Rate ISA Rate In 2026?
The current Santander 1 Year Fixed Rate ISA pays 4.45% AER tax-free and is fixed until 1 October 2027.
What Is The Minimum Deposit For The Santander 1 Year Fixed Rate ISA?
The minimum balance is normally £500. Santander also permits a zero-balance opening where an eligible ISA worth at least £500 is being transferred in.
Can I Add More Money After Opening The Santander Fixed ISA?
Yes, subject to the account and ISA limits, but Santander currently says deposits into this issue must be made by 31 October 2026.
Can I Withdraw Money Early From The Santander Fixed Rate ISA?
Yes, but Santander generally requires the full account to be closed or transferred. A charge equal to 120 days’ interest normally applies outside the cancellation period.
Can I Transfer An Existing ISA To Santander?
Yes. Santander accepts qualifying ISA transfers, although transfer requests and funds must arrive within its specified deadlines.
How Much Interest Could £10,000 Earn At 4.45%?
A full year at 4.45% would produce approximately £445 in interest on £10,000. The actual amount may differ depending on when the money is deposited.
Is The Santander 1 Year Fixed Rate ISA Protected By The FSCS?
Eligible deposits are protected under FSCS rules, currently up to £120,000 per eligible person, per authorised firm.
