What interest rate does the Santander 3 Year Fixed Rate ISA pay?

The Santander 3 Year Fixed Rate ISA pays 4.85% AER fixed.

How much interest could I earn?

Saving £10,000 for 3 years would earn about £1,527 at 4.85% AER. This assumes the rate stays the same and interest stays in the account.

How much can I pay in?

You can deposit at least £500 and up to £2,000,000.

Can I withdraw my money?

No. Withdrawals aren't allowed until the account matures.

When is interest paid?

You can choose to have interest paid annually or at the end of the term.

Who can open this account?

New and existing Santander customers can open it. You can open it online, in branch or by phone.

Is my money protected?

Yes. Eligible deposits are protected by the Financial Services Compensation Scheme (FSCS) up to £120,000 per person, per banking licence.

Can I transfer an existing ISA in?

Yes, transfers in from other ISAs are accepted.

How does it compare with other three-year cash ISAs?

At 4.85% AER it ranks 9th of 28 three-year cash ISAs we track. The best pays 5.11% and the average is 4.61%.

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Cash ISA

Santander 3 Year Fixed Rate ISA Review

A competitive three-year cash ISA from Santander. It ranks 9th of 28 three-year cash ISAs we track.

Rate checked Oct 2026Got this account? Leave a review

Fixed rate · 3 years

4.85%AER

Rate checked Oct 2026Got this account? Leave a review

Protection

FSCS£120,000

Min balance

£500

Max balance

£2,000,000

Access

At maturity only

Interest paid

Annually/On maturity

Transfers in

Accepted

Santander is also paying £240 to switch your current account. Offer ends 7 October 2026.

See the switch offer

How It Stacks Up

Ranks 9th of 28

3-year cash ISAs we track

Above average

This account 4.85%

UK CPI (Aug 2026): 3.10%; Pays 1.75% more
Average 3-year cash ISA: 4.61%; Pays 0.24% more
Best 3-year cash ISA: 5.11%; Pays 0.26% less

Inflation: ONS. Averages and best rates: accounts on DepositScout.

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A Good Fit For

Pro: New and existing savers

Worth Weighing Up

Con: Your money is locked in for 3 years
Con: Not flexible: money you withdraw can't be replaced without using more allowance

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Estimated returns with Santander's Cash ISA

What you could earn with Santander's 3 Year Fixed Rate ISA.

Estimated interest

£1,000 saved

£153

At 4.85% AER

£5,000 saved

£763

At 4.85% AER

£10,000 saved

£1,527

At 4.85% AER

£2,000,000 saved

£305,342

At 4.85% AER

Estimated over the 36-month term, if the rate stays the same and interest is left in. Amounts outside the account's minimum or maximum aren't shown.

Our Expert Opinion on Santander 3 Year Fixed Rate ISA

Jan WatermannCo-Founder, DepositScout

Santander's 3 Year Fixed Rate ISA pays 4.85%, which sits above the cash ISA market average but still 0.27% behind the current market leader at 5.12%. At 1.75% above August 2026 CPI of 3.1%, the rate does at least beat inflation in real terms, which matters over a three-year commitment. The main catch is the complete lack of access until maturity, so this suits savers who are confident they will not need the money for three years. You need at least £500 to open it, and transfers in are accepted, which is a practical plus for consolidating existing ISA pots.

Compare Cash ISAs