Savings & Investing
NS&I vs Cash ISA vs Savings Account — Where to Put Your Cash
How NS&I savings, Cash ISAs, and standard savings accounts compare on interest rates, tax, access, and safety. UK comparison guide for 2026.
With Cash ISAs, NS&I products, and high-interest savings accounts all competing for your money, choosing where to save depends on how much you have, your tax rate, and what you need.
Quick Comparison
| Feature |
NS&I (Premium Bonds) |
Cash ISA |
Savings Account |
| Interest/return |
Prize fund rate ~4.00% (variable) |
4.0%–5.0% (best rates) |
4.0%–5.2% (best rates) |
| Tax treatment |
Tax-free (prizes) |
Tax-free (interest) |
Taxable (but PSA applies) |
| FSCS protection |
No — HM Treasury backed (100%, unlimited) |
Yes (£85,000 per banking group) |
Yes (£85,000 per banking group) |
| Access |
Instant (usually 3–5 working days) |
Instant or fixed term |
Instant or fixed term |
| Annual allowance |
N/A (max £50,000 holding) |
£20,000 per tax year |
No limit |
| Guaranteed return |
No — prizes are random |
Yes (if fixed rate) |
Yes (if fixed rate) |
| Minimum deposit |
£25 |
£1 (varies by provider) |
£1 (varies by provider) |
The Personal Savings Allowance (PSA)
Before choosing, understand how much savings interest you can earn tax-free.
| Tax band |
PSA (tax-free savings interest) |
Approx. savings to exceed PSA at 4.5% |
| Basic rate (20%) |
£1,000 |
~£22,000 |
| Higher rate (40%) |
£500 |
~£11,000 |
| Additional rate (45%) |
£0 |
Any interest is taxable |
If your total savings interest stays within the PSA, you pay no tax in a standard savings account. A Cash ISA provides no additional tax benefit in this case — just pick the highest rate.
When Each Option Wins
NS&I Premium Bonds — Best When:
| Situation |
Why |
| You have over £85,000 in savings |
HM Treasury backing has no upper limit — safer than FSCS |
| You are an additional rate taxpayer |
No PSA — Premium Bond prizes are tax-free |
| You are a higher rate taxpayer with PSA used |
Tax-free prizes avoid further tax |
| You enjoy the lottery element |
Chance of £1 million prize (very small odds) |
| You want a safe place to park cash |
Zero risk of loss |
Cash ISA — Best When:
| Situation |
Why |
| You are a higher or additional rate taxpayer with savings above PSA |
All interest is permanently tax-free |
| You want to build a long-term tax-free pot |
ISA allowance carries over year to year |
| You are saving for a specific goal over multiple years |
Tax-free compounding |
| Cash ISA rate matches or beats savings accounts |
No downside vs savings account |
Savings Account — Best When:
| Situation |
Why |
| You are a basic rate taxpayer with under ~£22,000 in savings |
PSA covers your interest — ISA not needed |
| The best savings rate is significantly higher than the best Cash ISA rate |
More money > tax shelter |
| You want a fixed-term bond with a high rate |
Fixed savings accounts often pay more than fixed Cash ISAs |
| You need instant access to a large emergency fund |
Easy access savings accounts are flexible |
Rate Comparison (Illustrative — Check Current Rates)
| Product type |
Easy access |
1-year fixed |
2-year fixed |
| Best savings account |
4.5–5.0% AER |
4.5–5.0% AER |
4.2–4.8% AER |
| Best Cash ISA |
4.3–4.8% AER |
4.3–4.8% AER |
4.0–4.5% AER |
| NS&I Premium Bonds |
~4.0% average (prizes) |
N/A |
N/A |
| NS&I Income Bonds |
~4.0% |
N/A |
N/A |
| NS&I Direct Saver |
~3.5% |
N/A |
N/A |
Savings accounts often pay slightly higher rates than equivalent Cash ISAs because they rely on the PSA for tax efficiency rather than ISA wrapper.
Tax Comparison — How Much You Keep
Basic Rate Taxpayer with £20,000 Savings
| Product |
Gross interest (4.5%) |
Tax |
Net interest |
| Savings account |
£900 |
£0 (within £1,000 PSA) |
£900 |
| Cash ISA |
£900 |
£0 (ISA tax-free) |
£900 |
| Premium Bonds (~4%) |
~£800 (average prizes) |
£0 (tax-free) |
~£800 |
At this level, savings account and Cash ISA are equivalent. Premium Bonds return less.
Higher Rate Taxpayer with £50,000 Savings
| Product |
Gross interest (4.5%) |
Tax |
Net interest |
| Savings account |
£2,250 |
£700 (£2,250 – £500 PSA = £1,750 × 40%) |
£1,550 |
| Cash ISA (£20k) + savings (£30k) |
£900 (ISA) + £1,350 (savings) |
£340 (£1,350 – £500 PSA = £850 × 40%) |
£1,910 |
| Premium Bonds (£50k max) |
~£2,000 (average prizes) |
£0 |
~£2,000 |
At this level, Premium Bonds and Cash ISA provide meaningful tax savings.
Additional Rate Taxpayer with £50,000 Savings
| Product |
Gross interest (4.5%) |
Tax |
Net interest |
| Savings account |
£2,250 |
£1,012 (£2,250 × 45%) |
£1,238 |
| Cash ISA (£20k) + savings (£30k) |
£900 (ISA) + £1,350 (savings) |
£608 (£1,350 × 45%) |
£1,643 |
| Premium Bonds (£50k max) |
~£2,000 (average prizes) |
£0 |
~£2,000 |
For additional rate taxpayers, Premium Bonds and Cash ISAs are significantly better.
NS&I Product Range
| Product |
Rate (approx.) |
Access |
Tax treatment |
Min/Max |
| Premium Bonds |
~4.0% (prize fund rate) |
Instant (3–5 days) |
Tax-free |
£25 / £50,000 |
| Income Bonds |
~4.0% (variable) |
Instant |
Taxable (but uses PSA) |
£500 / £1m |
| Direct Saver |
~3.5% (variable) |
Instant |
Taxable (but uses PSA) |
£1 / £2m |
| Green Savings Bonds |
~3.5–4.0% (fixed 3 years) |
Fixed term |
Taxable |
£100 / £100,000 |
| Guaranteed Growth/Income Bonds |
~4.0% (fixed 1 year) |
Fixed term (penalty for early withdrawal) |
Taxable |
£500 / £1m |
Where to Put Savings — Decision Tree
| Your situation |
Best option |
| Basic rate, savings under £20,000 |
Whichever pays the highest rate (savings account or Cash ISA) |
| Basic rate, savings over £22,000 |
Use Cash ISA allowance first, then best savings account |
| Higher rate, savings under £11,000 |
Whichever pays the highest rate |
| Higher rate, savings over £11,000 |
Cash ISA + Premium Bonds + savings account (in that order) |
| Additional rate, any amount |
Cash ISA (£20,000) + Premium Bonds (up to £50,000) + NS&I/savings for the rest |
| Over £85,000 total savings |
Spread across banking groups for FSCS cover, or use NS&I (unlimited Treasury backing) |
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