ISAs UK: Cash, Stocks & Shares, Lifetime, Junior and Transfer Rules

ISA vs Premium Bonds 2026 — Which Is Better for Your Savings?

Compare ISAs and Premium Bonds for your savings. Understand returns, tax efficiency, risks, accessibility, and which is better for emergency funds, short-term savings, and long-term growth.

Savings and investment information is for educational purposes only. The value of investments can go down as well as up. Cash savings up to £85,000 per person per institution are protected by the FSCS.

ISAs and Premium Bonds are both popular tax-free savings options in the UK. Here’s how to choose between them — or use both.

Read more: See our Isas guide for a complete overview of this topic.

Quick Comparison

FeatureCash ISAPremium Bonds
ProviderBanks, building societiesNS&I (government-backed)
ReturnsFixed or variable interestPrize-based (average 4%)
Guaranteed returnYesNo (luck-based)
Tax statusTax-freeTax-free
Annual limit£20,000£50,000 maximum holding
MinimumOften £1£25
AccessUsually instant3 working days
SafetyFSCS protected (£85k)100% government-backed

How Each Works

Cash ISA

AspectDetail
What it isTax-free savings account
InterestPaid monthly or annually
RatesFixed or variable (3-5% typical)
Limit£20,000 per tax year
AccessUsually easy access (some fixed rate)

Premium Bonds

AspectDetail
What it isPrize-based savings with NS&I
ReturnNo interest — prize draws only
Prize fund rateCurrently 4%
Prize range£25 to £1 million
Draw frequencyMonthly
Each £1 BondOne entry in draw

Returns Comparison

Cash ISA Returns 2026

ISA TypeTypical Rate£10,000 Earns
Easy access3.5-4.5%£350-£450/year
1-year fixed4.0-4.75%£400-£475/year
2-year fixed4.0-4.5%£400-£450/year
Lifetime ISA+ 25% bonus+ £1,000 bonus on £4k

Premium Bonds Returns

Prize Fund RateAverage Return£10,000 Earns (Average)
4.00%4.00%£400/year (average)

Important: 4% is an average. Your actual return varies based on luck.

Premium Bonds Prize Distribution

PrizeOdds (per £1 bond)Typical Monthly Prizes
£1 million1 in 54,591,086,0002
£100,0001 in 5,459,108,60020
£50,0001 in 2,729,554,30040
£25,0001 in 1,364,777,15080
£10,0001 in 545,910,860200
£5,0001 in 181,970,287600
£1,0001 in 29,661,9553,680
£5001 in 14,830,9777,360
£1001 in 740,694147,364
£501 in 148,139736,821
£251 in 21,000~5.2 million

What You’re Likely to Win (Premium Bonds)

HoldingExpected Annual ReturnReality
£1,000£40 (average)Likely £0-£100
£10,000£400 (average)Likely £100-£600
£50,000£2,000 (average)Likely £1,500-£2,500

With smaller holdings, you may win nothing for months. The more you hold, the closer to the average you’ll likely get.

Tax Efficiency

Both Are Tax-Free

Tax SituationCash ISAPremium Bonds
Basic rate taxpayerTax-freeTax-free
Higher rate taxpayerTax-freeTax-free
Additional rate taxpayerTax-freeTax-free

Compared to Normal Savings

TaxpayerPersonal Savings AllowanceAfter Using PSA
Basic rate (20%)£1,000Interest taxed at 20%
Higher rate (40%)£500Interest taxed at 40%
Additional rate (45%)£0All interest taxed at 45%

Example: £50,000 earning 4% = £2,000 interest

TaxpayerTax on Regular SavingsTax in ISA/Premium Bonds
Basic rate£200 (after £1k allowance)£0
Higher rate£600 (after £500 allowance)£0
Additional rate£900 (no allowance)£0

Safety and Security

Cash ISA Protection

ProtectionLevel
FSCS guarantee£85,000 per institution
Joint accounts£170,000 per institution
Multiple ISAsEach institution separate

Premium Bonds Protection

ProtectionLevel
Government-backed100% — unlimited
NS&IBacked by HM Treasury
No limitFull amount protected

Winner for safety: Premium Bonds — no limit on protection.

Access and Flexibility

Cash ISA Access

ISA TypeAccess
Easy accessInstant (same day)
Notice account30-120 days notice
Fixed rateLocked for term (penalties apply)

Premium Bonds Access

RequestTimeline
Cash out online3 working days
Cash out by phone/postUp to 8 working days
Partial withdrawalMinimum £25

Who Should Choose What

Cash ISA Is Better For

SituationWhy ISA
Guaranteed returns neededInterest is certain
Emergency fundInstant access available
Regular income from savingsPredictable interest
Smaller savings amountsSmall holdings unlikely to win
Short-term goalsKnow exact return

Premium Bonds Are Better For

SituationWhy Premium Bonds
Higher/additional rate taxpayerTax-free + no PSA restriction
Large savings (£30k+)Returns closer to average
Already used ISA allowanceExtra tax-free savings
Enjoy the excitementPrize draw element
Maximum security wanted100% government-backed
Long-term savingsTime to even out lucky/unlucky months

Using Both

StrategyHow
ISA for guaranteed returnsUse £20k allowance
Premium Bonds for extraAbove ISA allowance
Split emergency fundSome each
Maximise tax efficiencyBoth are tax-free

Considering Other Options

Stocks & Shares ISA

Factorvs Cash ISAvs Premium Bonds
Potential returnsHigher (7-10% long-term)Higher
RiskCan lose moneyMore risky
Time horizon5+ years recommendedLong-term only
TaxTax-free gainsTax-free

Best for: Long-term savings (5+ years) where you can accept short-term losses.

Lifetime ISA

FactorDetail
Bonus25% on contributions up to £4,000/year
UseFirst home or retirement (after 60)
Limit£4,000/year (counts toward £20k total)
Penalty25% if withdrawn for other purposes

Best for: First-time buyers or additional retirement savings.

Regular Savings Accounts

FactorDetail
RatesOften 5-6%
Limit£25-£500/month typically
TaxInterest is taxable
Best forBuilding regular savings habit

Strategies by Savings Goal

Emergency Fund (3-6 Months Expenses)

RecommendationReason
Easy-access Cash ISAInstant access, guaranteed
Or splitHalf Cash ISA, half Premium Bonds
Amount£5,000-£15,000 typically

Short-Term Goal (1-3 Years)

GoalRecommendation
House depositCash ISA (fixed if rate good)
Car purchaseEasy-access Cash ISA
HolidayCash ISA or regular saver

Medium-Term (3-5 Years)

SituationRecommendation
May need some flexibilityMix of Cash ISA and Premium Bonds
Could accept some riskAdd Stocks & Shares ISA element
Maximum tax efficiencyUse full ISA allowance first

Long-Term (5+ Years)

ApproachRecommendation
Growth focusStocks & Shares ISA
Low riskCash ISA + Premium Bonds
BalancedMix all three

How to Open Each

Opening a Cash ISA

StepAction
1Compare rates (MoneySavingExpert, Which?)
2Check terms (access, minimum, penalties)
3Apply online or in branch
4Provide ID and proof of address
5Transfer or deposit funds

Opening Premium Bonds

StepAction
1Go to nsandi.com
2Create account
3Provide ID verification
4Deposit £25-£50,000
5First eligible draw: following month

Common Questions

Can I Have Both ISA and Premium Bonds?

AnswerDetail
YesNo restriction on having both
ISA limit£20,000/year
Premium Bonds limit£50,000 total
Combined maximum£70,000

Do Premium Bonds Beat Inflation?

Current SituationAssessment
Prize fund rate4%
Inflation (CPI)~2-3%
Real return1-2% (positive currently)

Note: Rates change — when prize fund rate was 1%, Premium Bonds lost to inflation.

What Happens to Premium Bonds When I Die?

ScenarioOutcome
DeathBonds can stay in draw for 12 months
After 12 monthsExecutors must cash in
Prizes wonPaid to estate
No inheritance tax issuesValue included in estate

Can Children Have These?

ProductChildren Allowed?
Junior ISAYes — up to £9,000/year
Cash ISA16+ only
Stocks & Shares ISA18+ only
Premium BondsYes — any age (adult buys for them)

Summary: ISA vs Premium Bonds

If You WantChoose
Guaranteed returnsCash ISA
100% government protectionPremium Bonds
Instant accessEasy-access Cash ISA
Excitement/chance of big winPremium Bonds
Maximum savings (£50k+)Both — use ISA allowance + Premium Bonds
Best ratesCompare Cash ISAs
SimplicityEither works

Sources

  1. NS&I — Premium Bonds
  2. UK Debt Management Office — Gilts