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.
·6 min read
ISAs and Premium Bonds are both popular tax-free savings options in the UK. Here’s how to choose between them — or use both.
Quick Comparison
Feature
Cash ISA
Premium Bonds
Provider
Banks, building societies
NS&I (government-backed)
Returns
Fixed or variable interest
Prize-based (average 4%)
Guaranteed return
Yes
No (luck-based)
Tax status
Tax-free
Tax-free
Annual limit
£20,000
£50,000 maximum holding
Minimum
Often £1
£25
Access
Usually instant
3 working days
Safety
FSCS protected (£85k)
100% government-backed
How Each Works
Cash ISA
Aspect
Detail
What it is
Tax-free savings account
Interest
Paid monthly or annually
Rates
Fixed or variable (3-5% typical)
Limit
£20,000 per tax year
Access
Usually easy access (some fixed rate)
Premium Bonds
Aspect
Detail
What it is
Prize-based savings with NS&I
Return
No interest — prize draws only
Prize fund rate
Currently 4%
Prize range
£25 to £1 million
Draw frequency
Monthly
Each £1 Bond
One entry in draw
Returns Comparison
Cash ISA Returns 2026
ISA Type
Typical Rate
£10,000 Earns
Easy access
3.5-4.5%
£350-£450/year
1-year fixed
4.0-4.75%
£400-£475/year
2-year fixed
4.0-4.5%
£400-£450/year
Lifetime ISA
+ 25% bonus
+ £1,000 bonus on £4k
Premium Bonds Returns
Prize Fund Rate
Average 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
Prize
Odds (per £1 bond)
Typical Monthly Prizes
£1 million
1 in 54,591,086,000
2
£100,000
1 in 5,459,108,600
20
£50,000
1 in 2,729,554,300
40
£25,000
1 in 1,364,777,150
80
£10,000
1 in 545,910,860
200
£5,000
1 in 181,970,287
600
£1,000
1 in 29,661,955
3,680
£500
1 in 14,830,977
7,360
£100
1 in 740,694
147,364
£50
1 in 148,139
736,821
£25
1 in 21,000
~5.2 million
What You’re Likely to Win (Premium Bonds)
Holding
Expected Annual Return
Reality
£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 Situation
Cash ISA
Premium Bonds
Basic rate taxpayer
Tax-free
Tax-free
Higher rate taxpayer
Tax-free
Tax-free
Additional rate taxpayer
Tax-free
Tax-free
Compared to Normal Savings
Taxpayer
Personal Savings Allowance
After Using PSA
Basic rate (20%)
£1,000
Interest taxed at 20%
Higher rate (40%)
£500
Interest taxed at 40%
Additional rate (45%)
£0
All interest taxed at 45%
Example: £50,000 earning 4% = £2,000 interest
Taxpayer
Tax on Regular Savings
Tax 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
Protection
Level
FSCS guarantee
£85,000 per institution
Joint accounts
£170,000 per institution
Multiple ISAs
Each institution separate
Premium Bonds Protection
Protection
Level
Government-backed
100% — unlimited
NS&I
Backed by HM Treasury
No limit
Full amount protected
Winner for safety: Premium Bonds — no limit on protection.
Access and Flexibility
Cash ISA Access
ISA Type
Access
Easy access
Instant (same day)
Notice account
30-120 days notice
Fixed rate
Locked for term (penalties apply)
Premium Bonds Access
Request
Timeline
Cash out online
3 working days
Cash out by phone/post
Up to 8 working days
Partial withdrawal
Minimum £25
Who Should Choose What
Cash ISA Is Better For
Situation
Why ISA
Guaranteed returns needed
Interest is certain
Emergency fund
Instant access available
Regular income from savings
Predictable interest
Smaller savings amounts
Small holdings unlikely to win
Short-term goals
Know exact return
Premium Bonds Are Better For
Situation
Why Premium Bonds
Higher/additional rate taxpayer
Tax-free + no PSA restriction
Large savings (£30k+)
Returns closer to average
Already used ISA allowance
Extra tax-free savings
Enjoy the excitement
Prize draw element
Maximum security wanted
100% government-backed
Long-term savings
Time to even out lucky/unlucky months
Using Both
Strategy
How
ISA for guaranteed returns
Use £20k allowance
Premium Bonds for extra
Above ISA allowance
Split emergency fund
Some each
Maximise tax efficiency
Both are tax-free
Considering Other Options
Stocks & Shares ISA
Factor
vs Cash ISA
vs Premium Bonds
Potential returns
Higher (7-10% long-term)
Higher
Risk
Can lose money
More risky
Time horizon
5+ years recommended
Long-term only
Tax
Tax-free gains
Tax-free
Best for: Long-term savings (5+ years) where you can accept short-term losses.
Lifetime ISA
Factor
Detail
Bonus
25% on contributions up to £4,000/year
Use
First home or retirement (after 60)
Limit
£4,000/year (counts toward £20k total)
Penalty
25% if withdrawn for other purposes
Best for: First-time buyers or additional retirement savings.
Regular Savings Accounts
Factor
Detail
Rates
Often 5-6%
Limit
£25-£500/month typically
Tax
Interest is taxable
Best for
Building regular savings habit
Strategies by Savings Goal
Emergency Fund (3-6 Months Expenses)
Recommendation
Reason
Easy-access Cash ISA
Instant access, guaranteed
Or split
Half Cash ISA, half Premium Bonds
Amount
£5,000-£15,000 typically
Short-Term Goal (1-3 Years)
Goal
Recommendation
House deposit
Cash ISA (fixed if rate good)
Car purchase
Easy-access Cash ISA
Holiday
Cash ISA or regular saver
Medium-Term (3-5 Years)
Situation
Recommendation
May need some flexibility
Mix of Cash ISA and Premium Bonds
Could accept some risk
Add Stocks & Shares ISA element
Maximum tax efficiency
Use full ISA allowance first
Long-Term (5+ Years)
Approach
Recommendation
Growth focus
Stocks & Shares ISA
Low risk
Cash ISA + Premium Bonds
Balanced
Mix all three
How to Open Each
Opening a Cash ISA
Step
Action
1
Compare rates (MoneySavingExpert, Which?)
2
Check terms (access, minimum, penalties)
3
Apply online or in branch
4
Provide ID and proof of address
5
Transfer or deposit funds
Opening Premium Bonds
Step
Action
1
Go to nsandi.com
2
Create account
3
Provide ID verification
4
Deposit £25-£50,000
5
First eligible draw: following month
Common Questions
Can I Have Both ISA and Premium Bonds?
Answer
Detail
Yes
No 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 Situation
Assessment
Prize fund rate
4%
Inflation (CPI)
~2-3%
Real return
1-2% (positive currently)
Note: Rates change — when prize fund rate was 1%, Premium Bonds lost to inflation.