Best Building Society Cash ISA Rates UK 2026

by
UK Cash ISA Rate Comparison · Reviewed 22 September 2026

Best Building Society Cash ISA Rates UK 2026

The best building society Cash ISA rates depend on how long you can leave the money untouched. In the major building-society ranges checked for this September 2026 comparison, Skipton currently reaches 4.76% tax-free/AER fixed on a five-year Cash ISA, while Nationwide offers 4.70% over five years and 4.65% over three years.

Shorter terms tell a different story. Nationwide, Leeds Building Society and Principality currently offer selected one-year fixed Cash ISAs at 4.50% tax-free/AER. If access matters more than fixing the rate, Leeds currently advertises 4.16% AER variable on its Online Access Cash ISA for qualifying balances, while Principality’s Online Bonus Triple Access Cash ISA pays a higher 4.25% variable rate but restricts withdrawals.

Compare Cash ISA Rates Access Cash ISAs Fixed Cash ISAs
Important rate warning: Cash ISA issues can be withdrawn or replaced quickly. The rates below are a dated comparison of selected major UK building societies, not a claim that every Cash ISA in the UK has been ranked. Check the provider’s live Summary Box immediately before applying or transferring an ISA.

Meaningful editorial review: 22 September 2026. ISA rates, issue numbers, funding windows, early-access penalties and eligibility can change after publication.

Best Building Society Cash ISA Rates: Quick Answers

4.76% Skipton 5 Year Fixed Rate Cash ISA — highest fixed rate in this selected comparison.
4.70% Nationwide 5 Year Fixed Rate Cash ISA.
4.65% Nationwide 3 Year Fixed Rate Cash ISA and Newcastle 5 Year Fixed Rate ISA.
4.55% Nationwide 2 Year Fixed Rate Cash ISA.
4.50% Selected one-year fixed rates from Nationwide, Leeds and Principality.
4.25% Principality Online Bonus Triple Access Cash ISA, variable with withdrawal limits.
4.16% Leeds Online Access Cash ISA Issue 22, variable with online access.
£20,000 Overall ISA subscription allowance for the 2026/27 tax year.
£120,000 Current standard FSCS deposit-protection limit per eligible person, per authorised firm.
Fast answer: for a lump sum you can leave alone, compare fixed Cash ISAs by term. For money you may need during the year, start with easy or limited access even if the headline rate is slightly lower.

Building Society Cash ISA Rates Compared: September 2026

These accounts are not directly interchangeable. A five-year fixed ISA gives a different balance of rate and access from a one-year ISA or an online access ISA, so compare within the term and access pattern you actually need.

Cash ISA
Rate
Type
Minimum
Important access rule
Skipton 5 Year Fixed Rate Cash ISA
5 years Fixed
4.76%
Fixed Cash ISA
£1
No partial withdrawals. Early closure is currently subject to a 365-day interest penalty.
Nationwide 5 Year Fixed Rate Cash ISA
5 years Fixed
4.70%
Fixed Cash ISA
£1
Withdrawal before maturity closes the ISA and an early-access charge applies.
Nationwide 3 Year Fixed Rate Cash ISA
3 years Fixed
4.65%
Fixed Cash ISA
£1
Designed for a lump sum that can remain fixed for three years; early access closes the ISA and carries a charge.
Newcastle 5 Year Fixed Rate ISA Issue 87
5 years Fixed
4.65%
Fixed Cash ISA
£1
Withdrawals are permitted subject to a current 365-day loss-of-interest condition; the current issue is branch application.
Nationwide 2 Year Fixed Rate Cash ISA
2 years Fixed
4.55%
Fixed Cash ISA
£1
No normal partial access during the term; closure and an early-access charge apply if money is taken early.
Nationwide 1 Year Fixed Rate Cash ISA
1 year Fixed
4.50%
Fixed Cash ISA
£1
Fund during the application; Nationwide currently says the ISA cannot be topped up after it is opened.
Leeds 1 Year Fixed Rate Cash ISA Issue 240
1 year Fixed
4.50%
Fixed Cash ISA
£100 for headline rate
Fixed until 4 October 2027 under the current issue. Read the Summary Box for early-access and transfer conditions.
Principality 1 Year Fixed Rate Cash ISA
1 year Fixed
4.50%
Fixed Cash ISA
£500
No normal withdrawals. Online or branch opening is currently available.
Principality Online Bonus Triple Access Cash ISA
Limited access Variable
4.25%
Limited-access Cash ISA
£1
Three withdrawals each tax year. Current rate includes a 1.90% variable bonus for the first 12 months.
Leeds Online Access Cash ISA Issue 22
Online access Variable
4.16%
Online access Cash ISA
£1,000 for headline rate
Access your money at any time. Balances below £1,000 currently receive only 0.05% AER.
Rate context: the Bank of England held Bank Rate at 3.75% on 17 September 2026. Cash ISA rates do not have to match Bank Rate, and fixed rates reflect providers’ expectations and funding needs over the chosen term.

Best One-Year Building Society Cash ISA Rates Checked

A one-year fix can make sense when you want certainty but do not want to lock money away for several years. Three large building societies in this comparison currently offer 4.50% on selected one-year fixed Cash ISAs.

Nationwide

1 Year Fixed Rate Cash ISA

4.50% AER/tax-free fixed
  • Open from £1.
  • UK residents aged 18+.
  • Online and branch management.
  • Fund during the application under the current terms.
  • Early access means closing the ISA and paying an access charge.
Leeds

1 Year Fixed Rate Cash ISA Issue 240

4.50% tax-free p.a./AER fixed
  • Current fixed date: 4 October 2027.
  • Headline rate applies from the required qualifying balance.
  • ISA transfers can be relevant depending on the current terms.
  • Check the funding deadline before opening.
Principality

1 Year Fixed Rate Cash ISA

4.50% tax-free/AER fixed
  • £500 minimum opening deposit.
  • Online or branch opening.
  • No normal withdrawals during the term.
  • Interest can currently be paid yearly or monthly.
Newcastle

1 Year Fixed Rate ISA Issue 128

4.35% tax-free PA/AER fixed
  • Open from £1.
  • Fixed until 24 August 2027 under the current issue.
  • Online or branch application.
  • Early withdrawal currently carries a 90-day loss of interest.
Coventry

Fixed Rate ISA (339)

4.00% tax-free p.a./AER
  • Fixed until 31 December 2027.
  • Open from £1.
  • Current and previous years’ ISA transfers accepted.
  • Full closure can be available subject to an interest charge.
Skipton

1 Year Fixed Rate Cash ISA

4.00% tax-free pa/AER fixed
  • Open from £1.
  • No partial withdrawals.
  • Early closure currently carries a 60-day interest penalty.
  • ISA transfers can be accepted subject to the live terms.
Useful comparison: if you are deciding between several one-year ISAs paying the same 4.50%, compare the funding window, minimum balance, transfer process, early-access penalty and how you prefer to manage the account.

Two-Year Fixed Cash ISA Rates Compared

A two-year Cash ISA offers more rate certainty than a one-year deal without committing for three to five years. The cost is reduced flexibility if you need the money early.

Nationwide — 4.55% Current 2 Year Fixed Rate Cash ISA. £1 minimum, with early closure and an access charge if money is withdrawn before maturity.
Newcastle — 4.40% 2 Year Fixed Rate ISA Issue 125. £1 minimum; withdrawals are currently subject to 120 days’ loss of interest.
Principality — 4.35% 2 Year Fixed Rate Cash ISA Issue 440. £500 minimum, online/branch/post management and no normal withdrawals.
Skipton — 4.30% 2 Year Fixed Rate Cash ISA. £1 minimum; early closure currently carries a 180-day interest penalty.
Coventry — 4.10% Fixed Rate ISA (340), fixed until 31 December 2028 rather than exactly two years from every opening date.
Check the actual maturity date. Some building societies describe products by a fixed calendar maturity date rather than a simple “two years from opening” period. A late applicant may therefore receive a shorter effective term.

Three-Year and Five-Year Building Society Cash ISA Rates

Longer fixed ISAs can protect a rate if market rates fall, but they create more risk that your money is tied up when you need it or that newer accounts later pay more.

Provider
Rate
Term
Minimum
Early access
Skipton
4.76%
5 years
£1
Close the ISA early; current penalty is 365 days’ interest.
Nationwide
4.70%
5 years
£1
Withdrawal closes the ISA and an early-access charge applies.
Nationwide
4.65%
3 years
£1
Withdrawal closes the ISA and an early-access charge applies.
Newcastle
4.65%
5 years
£1
Current issue permits withdrawal subject to 365 days’ loss of interest.
Skipton
4.50%
3 years
£1
Early closure currently carries a 240-day interest penalty.
Principality
4.30%
3 or 5 years
£500
No normal withdrawals; closure or ISA transfer can have an interest cost under the product terms.
Five years is a long commitment. A higher rate is useful only if the money can genuinely stay in the ISA. Keep emergency cash and known near-term spending outside a long fixed term.

Best Access Cash ISA Rates Among the Building Societies Checked

Access accounts are easier to use for emergency savings or money you may need during the tax year. The trade-off is that most rates are variable and some of the strongest rates limit how often you can withdraw.

Limited access

Principality Online Bonus Triple Access Cash ISA

4.25% tax-free/AER variable
  • Open from £1.
  • Online account.
  • Three withdrawals each tax year.
  • Current rate includes a 1.90% variable bonus for 12 months.
  • Current underlying rate is 2.35% without that bonus.
Unlimited access

Leeds Online Access Cash ISA Issue 22

4.16% tax-free p.a./AER variable
  • Access your money at any time.
  • Online management.
  • Transfers from other ISAs allowed under the current terms.
  • £1,000 is needed to receive the headline rate.
  • Below £1,000, the current rate falls to 0.05%.
Single access

Newcastle Single Access ISA Issue 2

3.65% tax-free PA/AER variable
  • Open from £1.
  • One penalty-free withdrawal each anniversary year.
  • After a second withdrawal, the current rate falls to 1.70%.
  • Online or branch application.
Six access

Coventry 6 Access ISA – 1 Year (3)

3.60% tax-free p.a./AER variable
  • Open from £1.
  • Six charge-free withdrawals.
  • From the seventh withdrawal, a charge equal to 50 days’ interest currently applies.
  • Current and previous years’ ISA transfers are accepted.
Triple access

Nationwide 1 Year Triple Access ISA

3.30% AER/tax-free variable
  • Up to three withdrawals without reducing the rate.
  • After four or more withdrawals, the rate currently falls to 1.05% for the remainder of the term.
  • Online and branch management.
Unlimited access

Coventry Easy Access ISA (12)

2.00% tax-free p.a./AER variable
  • Unlimited withdrawals under the current terms.
  • Flexible ISA.
  • Open from £1.
  • Transfers from current and previous tax-year ISAs are allowed.
Access matters as much as rate. Someone who expects four or five withdrawals may be better served by an unrestricted account than by a higher-paying three-access ISA that becomes inconvenient later.

Fixed Cash ISA vs Easy or Limited Access ISA

Fixed Cash ISA

  • Rate is guaranteed for the term.
  • Often useful for a lump sum.
  • Can protect your return if savings rates fall.
  • Usually restricts normal withdrawals.
  • Early closure or transfer can cost interest.
  • Funding windows can be short.

Access Cash ISA

  • Useful when you may need the money.
  • Rate is normally variable.
  • Some accounts allow unlimited withdrawals.
  • Higher-paying accounts may restrict withdrawal frequency.
  • Flexible ISA status can matter if you withdraw and replace money.
  • Bonus rates can expire after 12 months.
Do not put your full emergency fund into a fixed ISA merely for an extra fraction of a percentage point. The cost of breaking the fix can be much more important than the extra interest.

Cash ISA Allowance for the 2026/27 Tax Year

For the tax year running from 6 April 2026 to 5 April 2027, the overall adult ISA subscription limit remains £20,000. Under the current 2026/27 rules, that allowance can be allocated between permitted ISA types subject to the applicable ISA rules.

£20,000 Overall ISA subscription limit for 2026/27.
6 April Start of the UK tax year.
5 April Final day of the 2026/27 tax year.
Tax-free Interest inside a qualifying Cash ISA does not count towards your Personal Savings Allowance.
Unused ISA allowance does not roll forward. If part of the 2026/27 allowance remains unused after 5 April 2027, it cannot simply be added to the next tax year’s new subscription allowance.

Official GOV.UKIndividual Savings Account Rules

After opening this link:

  1. Check the annual ISA subscription limit for the current tax year.
  2. Review the types of ISA you are allowed to use.
  3. Check age and residency eligibility.
  4. Read the transfer rules before moving an existing ISA.
  5. If your contribution will be made after 5 April 2027, check the new tax-year rules instead of relying on 2026/27 limits.

Cash ISA Limit Change From 6 April 2027

HMRC published detailed rules in September 2026 confirming that the annual Cash ISA subscription limit will reduce to £12,000 for people under age 65 from 6 April 2027. The overall ISA subscription limit remains £20,000.

Under age 65 From 6 April 2027, the annual Cash ISA subscription limit will be £12,000 within the £20,000 overall ISA limit.
Age 65 or over The published rules retain a £20,000 annual Cash ISA limit for eligible investors aged 65 or over.
Overall ISA limit The overall ISA subscription limit remains £20,000 under the announced 2027 rules.
Start date The change applies from 6 April 2027, not during the current 2026/27 tax year.
Do not apply the £12,000 figure to the current tax year. Contributions made before the end of 5 April 2027 remain under the 2026/27 ISA rules.

Official HMRCCash ISA Limit Reduction From April 2027

After opening this link:

  1. Confirm the effective date of 6 April 2027.
  2. Read the £12,000 Cash ISA limit applying to people under 65.
  3. Read the separate £20,000 Cash ISA provision for people aged 65 or over.
  4. Distinguish the Cash ISA limit from the £20,000 overall ISA limit.
  5. Check any later HMRC update before making a 2027/28 subscription.

How to Transfer a Cash ISA Without Losing Its ISA Status

If you already have an ISA elsewhere, use the new provider’s formal ISA-transfer process. Do not normally withdraw the balance into your ordinary current account and then try to pay it into the new ISA.

Choose the new Cash ISA first.
Check that it accepts ISA transfers.
Read any transfer-in deadline on fixed issues.
Ask the new provider to start the ISA transfer.
Check the old ISA for an exit or interest penalty.
Do not manually withdraw unless you understand the specific flexible-ISA rules.
Keep the transfer confirmation.
Check the balance and tax-year treatment when the transfer completes.
Existing ISA transfers and new subscriptions are different. A properly completed ISA transfer can preserve the tax-free status of eligible existing ISA money. Your current-year subscription position still depends on the ISA contributions you have made under the rules for that tax year.

Cash ISA or Higher-Rate Ordinary Savings Account?

A Cash ISA is not automatically the highest-interest choice. Ordinary savings accounts can sometimes pay more, and many savers can receive some taxable-account interest without paying Income Tax because of the Personal Savings Allowance.

£1,000 Current Personal Savings Allowance for a basic-rate taxpayer.
£500 Current Personal Savings Allowance for a higher-rate taxpayer.
£0 Personal Savings Allowance for an additional-rate taxpayer.

Cash ISA may be particularly useful when

  • Your taxable savings interest is already near or above your available allowance.
  • You want to build a larger tax-free savings pot over several tax years.
  • You are a higher or additional-rate taxpayer.
  • You expect rates or your savings balance to make taxable interest more significant later.

Ordinary savings may still compete when

  • The ordinary account pays materially more.
  • Your savings interest remains within your available tax-free allowances.
  • You need account features unavailable in the ISA.
  • You have already used the ISA subscription allowance.
Compare the return you keep, not just the advertised rate. A higher taxable rate can beat a lower Cash ISA rate for someone who owes no tax on the interest, while the ISA can become more valuable as taxable interest grows.

Official HMRCCheck Your Tax-Free Savings Interest Allowance

After opening this link:

  1. Identify your Income Tax band.
  2. Check the Personal Savings Allowance that applies to you.
  3. Include interest from all ordinary taxable savings accounts.
  4. Read the starting-rate-for-savings rules if your other taxable income is relatively low.
  5. Compare your expected after-tax savings return with suitable Cash ISA rates.

How Much Cash ISA Money Is Protected by FSCS?

The standard Financial Services Compensation Scheme deposit limit is currently £120,000 per eligible person, per authorised firm. The limit increased from £85,000 on 1 December 2025.

£120,000 standard limit Applies to eligible deposits per person, per UK-authorised firm, subject to FSCS rules.
All eligible deposits count Your Cash ISA is considered together with other eligible deposits held under the same banking licence.
Brand names can mislead Two brands can share one authorised firm, so separate branding does not always create separate FSCS protection.
Temporary high balances Qualifying balances linked to certain major life events can currently receive protection up to £1.4 million for up to six months.
ISA status does not multiply FSCS protection. Holding £120,000 in a Cash ISA and another large savings balance with the same authorised firm does not automatically give each account its own separate £120,000 limit.

Official FSCSCheck the Current FSCS Deposit Protection Limit

After opening this link:

  1. Confirm the current standard deposit-protection limit.
  2. Read how shared banking licences affect protection.
  3. Add together eligible deposits held under the same authorised firm.
  4. Use the FSCS protection checker if you hold savings across several related brands.
  5. Check temporary-high-balance rules if a large balance came from a qualifying life event.

How to Choose a Building Society Cash ISA

Start with when you need the money. The rate comparison becomes much easier once you know whether the balance must remain accessible, can be fixed for one year or can genuinely be left for several years.

Choose access, one-year fixed, two-year fixed or longer term first.
Check the exact tax-free/AER rate.
Check whether the rate is fixed or variable.
Confirm the minimum balance needed for the headline rate.
Check the final funding date.
Read the early-access penalty in days of interest.
Check whether partial withdrawals are allowed.
Check whether the ISA is flexible.
Confirm ISA transfers are accepted.
Check online, branch or postal management.
Check the maturity destination account.
Confirm your total eligible balance remains within the FSCS position you expect.
Do not choose solely by provider name. The same building society can have a strong five-year ISA but a much less competitive easy-access account. Compare the exact account type rather than assuming one society is always cheapest or best.

Common Cash ISA Mistakes to Avoid

Choosing the highest five-year rate for short-term money A few extra tenths of a percentage point may not compensate for a large early-access penalty.
Ignoring minimum balance tiers Leeds’ current Online Access Cash ISA illustrates why this matters: dropping below £1,000 currently cuts the rate sharply.
Withdrawing instead of transferring Use the formal ISA-transfer process when preserving ISA status matters.
Assuming “easy access” and “limited access” are the same Three-access, six-access and single-access ISAs can reduce the rate or charge interest after the permitted number of withdrawals.
Missing a fixed-ISA funding deadline Some providers stop accepting additional money shortly after opening or when an issue is withdrawn.
Comparing only the rate Compare term, transfer-in rules, minimum balance, access cost and maturity process as well.
Using the 2027 limit too early The reduced £12,000 Cash ISA limit for people under 65 begins on 6 April 2027, not during the 2026/27 tax year.
Assuming ISA money has separate FSCS cover Cash ISA balances count with other eligible deposits held under the same authorised firm.

Related Building Society Savings Guides

Nationwide Building Society Savings Rates 2026 Yorkshire Building Society Savings Rates 2026 Leeds Building Society Savings & Account Guide West Brom Building Society Savings & ISA Guide Nationwide Building Society Member Guide

How This Cash ISA Comparison Was Checked

Nationwide live Cash ISA range checked.
Skipton fixed Cash ISA rates checked.
Leeds one-year fixed and online-access ISA details checked.
Principality fixed and access Cash ISA rates checked.
Newcastle fixed and access ISA range checked.
Coventry fixed and access ISA rates checked.
2026/27 £20,000 ISA limit checked.
6 April 2027 Cash ISA rule change checked against HMRC.
September 2026 Bank Rate checked.
Current £120,000 FSCS deposit limit checked.
ISA transfer and access restrictions reviewed.
Rates treated as dated facts rather than permanent product promises.

Rate-check date: 22 September 2026. Always use the live provider page as the final source before applying.

Independent Financial Information and Safety Notice

Building-society.org is an independent information website. It is not Nationwide Building Society, Skipton Building Society, Leeds Building Society, Principality Building Society, Newcastle Building Society, Coventry Building Society, HM Revenue & Customs, the Bank of England or the Financial Services Compensation Scheme.

This page does not provide personalised savings, investment or tax advice. It cannot open an ISA, transfer an existing ISA, access your account, confirm your tax position or determine which product is suitable for your circumstances.

Verify before acting: rates, issue numbers, funding windows, transfer conditions, withdrawal penalties and ISA rules can change. Use the provider’s official website and current Summary Box before moving money.

Best Building Society Cash ISA Rates FAQs

1. What is the highest building society Cash ISA rate in this September 2026 comparison?

Skipton’s 5 Year Fixed Rate Cash ISA currently pays 4.76% tax-free/AER fixed, the highest rate among the selected major building-society Cash ISAs checked for this guide. It requires a five-year commitment and early closure currently carries a 365-day interest penalty.

2. What are the best one-year building society Cash ISA rates in 2026?

Nationwide, Leeds Building Society and Principality currently each have selected one-year fixed Cash ISAs paying 4.50% tax-free/AER in the ranges checked. Their minimum balances, funding windows and early-access terms differ, so compare the product conditions as well as the rate.

3. Which building society has a strong easy-access Cash ISA rate?

Leeds Building Society’s Online Access Cash ISA Issue 22 currently pays 4.16% tax-free p.a./AER variable on qualifying balances and allows access at any time. A balance of at least £1,000 is currently needed for the headline rate.

4. Which limited-access Cash ISA has a high rate?

Principality’s Online Bonus Triple Access Cash ISA currently pays 4.25% tax-free/AER variable. It permits three withdrawals each tax year and the headline rate currently includes a 1.90% variable bonus for the first 12 months.

5. How much can I put into a Cash ISA in 2026/27?

The overall adult ISA subscription allowance for the 2026/27 tax year is £20,000. The tax year runs from 6 April 2026 to 5 April 2027. Always check current GOV.UK ISA rules before subscribing.

6. Is the Cash ISA limit changing to £12,000?

Yes, but not until 6 April 2027. Under HMRC’s published rules, people under 65 will have a £12,000 annual Cash ISA subscription limit within the £20,000 overall ISA allowance. People aged 65 or over retain a £20,000 Cash ISA limit.

7. Can I transfer an old Cash ISA to a building society?

Many building society Cash ISAs accept transfers, but individual products differ. Use the receiving provider’s formal ISA-transfer process rather than withdrawing the money yourself if you want to preserve the ISA tax status.

8. Can I withdraw money from a fixed-rate Cash ISA?

Cash ISA rules allow providers to offer early closure or transfer, but fixed products commonly apply a substantial loss-of-interest charge. Partial withdrawals can also be prohibited. Check the exact Summary Box before fixing money you may need early.

9. Is a Cash ISA better than an ordinary savings account?

Not automatically. Cash ISA interest is tax-free, but an ordinary savings account may offer a higher rate and many people can receive some savings interest within the Personal Savings Allowance. Compare the after-tax return and account access that apply to you.

10. How much Cash ISA money is protected by FSCS?

The standard FSCS deposit-protection limit is currently £120,000 per eligible person, per authorised firm. Your eligible Cash ISA balance is combined with other eligible deposits held under the same banking licence when the standard protection limit is calculated.

Leave a Comment