Cash ISA vs Savings Account: Which Is Better in 2026?
Last updated: April 2026 | Reading time: 6 minutes
If you’ve got money to save, you’ve probably come across two options: a cash ISA and a regular savings account. Both keep your money safe and pay you interest — but they work quite differently, and choosing the wrong one could cost you.
What’s the difference?
A savings account pays you interest on your money. Simple. That interest is taxable income — though most people don’t actually pay tax on it because of the Personal Savings Allowance.
A cash ISA (Individual Savings Account) also pays you interest — but the interest is completely tax-free, forever. You can save up to £20,000 per tax year into ISAs (Cash ISAs are now capped at £12,000 from April 2026).
The Personal Savings Allowance — why most people don’t need an ISA yet
Here’s the bit that surprises most people: you probably don’t pay tax on your savings interest anyway. The Personal Savings Allowance (PSA) gives you a chunk of savings interest completely free of tax each year:
- Basic rate taxpayer (20%): £1,000 tax-free interest per year
- Higher rate taxpayer (40%): £500 tax-free interest per year
- Additional rate taxpayer (45%): No allowance
At current rates of around 4–5% AER, you’d need roughly £20,000–£25,000 in savings before your interest exceeds the basic rate allowance. If you have less than that saved, a regular savings account with the best rate is often the better choice.
When a Cash ISA makes more sense
Once your savings grow beyond £20,000–£25,000, a cash ISA starts to matter more because:
- Your interest income exceeds your PSA, making it taxable
- An ISA shelters all that interest from tax permanently
- The ISA allowance rolls over — money saved in previous years stays protected
- Cash ISAs make strong sense for higher rate taxpayers whose PSA is only £500
Current rate comparison (April 2026)
| Type | Best rate available | Provider |
|---|---|---|
| Easy access savings | 4.92% AER | Plum |
| Easy access cash ISA | 4.6% AER | Trading 212 |
| Fixed savings (1 year) | 4.7% AER | Various |
| Fixed cash ISA (1 year) | 4.55% AER | Various |
Right now, the best easy access savings accounts pay more than the best cash ISAs. For most people with under £20,000 saved, a savings account wins on pure interest.
The simple decision guide
Choose a savings account if:
- You have under £20,000 saved
- You’re a basic rate taxpayer
- You want the highest possible interest rate
- You’re just starting your savings journey
Choose a cash ISA if:
- You have over £20,000 saved
- You’re a higher or additional rate taxpayer
- You want to shelter a large lump sum from tax long-term
- You’re planning to transfer existing ISA savings
Can you have both?
Yes — and many people do. A common approach is to keep an easy access savings account for your emergency fund and short-term goals, while also contributing to a cash ISA for longer-term tax-free growth. Your £20,000 annual ISA allowance refreshes every April.
Use our calculator to compare
Our savings calculator lets you plug in your balance and interest rate to see exactly what you’d earn over 1, 2, or 5 years — useful for seeing whether the tax difference actually matters for your situation.
Key takeaways
- Most people with under £20,000 saved are better off with a high-rate easy access savings account
- Cash ISAs make more sense as your savings grow beyond £20,000–£25,000
- Higher rate taxpayers benefit from ISAs sooner
- You can hold both — they serve different purposes
- Always compare the actual rates, not just the tax wrapper
This article is for informational purposes only and does not constitute financial advice. Tax rules can change. Speak to a financial adviser if you’re unsure what’s right for your situation. Savings Account Calculator may receive a commission if you open an account through links on this page.