What interest rate does the Suffolk Building Society 1 Year Fixed Rate ISA pay?

The Suffolk Building Society 1 Year Fixed Rate ISA pays 4.35% AER fixed.

How much interest could I earn?

Saving £10,000 for 1 year would earn about £435 at 4.35% 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 £1,000 and up to £500,000.

Can I withdraw my money?

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

When is interest paid?

Interest is paid annually or monthly.

Who can open this account?

You can open it online, in branch or by post.

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 one-year cash ISAs?

At 4.35% AER it ranks 29th of 47 one-year cash ISAs we track. The best pays 4.92% and the average is 4.37%.

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Cash ISA

Suffolk Building Society 1 Year Fixed Rate ISA Review

A one-year cash ISA from Suffolk Building Society, with a £1,000 minimum deposit. It ranks 29th of 47 one-year cash ISAs we track.

Rate checked Oct 2026Got this account? Leave a review

Fixed rate · 1 year

4.35%AER

Rate checked Oct 2026Got this account? Leave a review

Protection

FSCS£120,000

Min balance

£1,000

Max balance

£500,000

Access

At maturity only

Interest paid

Annually or Monthly

Transfers in

Accepted

How It Stacks Up

Ranks 29th of 47

1-year cash ISAs we track

Just below average

This account 4.35%

UK CPI (Aug 2026): 3.10%; Pays 1.25% more
Average 1-year cash ISA: 4.37%; About the same
Best 1-year cash ISA: 4.92%; Pays 0.57% less

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

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A Good Fit For

Pro: Savers who want a monthly income

Worth Weighing Up

Con: Your money is locked in for 1 year
Con: You need at least £1,000 to open it

Good to Know

Also available to open and manage online.

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Estimated returns with Suffolk Building Society's Cash ISA

What you could earn with Suffolk Building Society's 1 Year Fixed Rate ISA.

Estimated interest

£1,000 saved

£43.50

At 4.35% AER

£5,000 saved

£218

At 4.35% AER

£10,000 saved

£435

At 4.35% AER

£500,000 saved

£21,750

At 4.35% AER

Estimated over one year, 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 Suffolk Building Society 1 Year Fixed Rate ISA

Jan WatermannCo-Founder, DepositScout

Suffolk Building Society's 1 Year Fixed Rate ISA pays 4.35%, which beats August 2026 CPI of 3.1% by 1.25%, so your money does grow in real terms, but the rate sits below the cash ISA market average and is 0.77% behind the category leader at 5.12%. You need at least £1,000 to open it, and the real catch is that there is no access until maturity, so this suits someone who can genuinely lock money away for a full year. ISA transfers in are accepted, which is useful if you want to consolidate existing ISA money.

Compare Cash ISAs