When Cash ISA actually beats regular savings
| Personal Savings Allowance (PSA) for 2025-26 | At 5.0% AER regular savings | At 5.0% AER Cash ISA |
|---|---|---|
| Basic-rate taxpayer (20%): GBP 1,000 of interest tax-free | GBP 20,000 = GBP 1,000 interest = entirely covered by basic-rate PSA | No tax regardless of balance, regardless of rate |
| Higher-rate (40%): GBP 500 tax-free | GBP 50,000 = GBP 2,500 interest, basic-rate taxpayer owes 20% on GBP 1,500 = GBP 300 tax | |
| Additional-rate (45%): GBP 0 tax-free | GBP 100,000 = GBP 5,000 interest, basic-rate tax: GBP 800; higher-rate tax: GBP 1,800; additional rate: GBP 2,250 |
Break-even: Cash ISA beats regular savings when your saved interest > your tax liability on regular savings.
| Who benefits from Cash ISA | Who does NOT benefit from Cash ISA |
|---|---|
| Higher-rate / additional-rate taxpayers (immediately tax-saving) | Basic-rate taxpayer with under GBP 20K (PSA covers all interest) |
| Anyone with savings over GBP 20K (PSA likely exhausted) | Investors with 5+ year horizon (Stocks ISA better expected return) |
| Forecasting future income to bump into higher rate | Borrowers - paying mortgage at 5%+ beats earning 5% interest on cash |
| Wanting "forever" tax-free wrapper for emergency fund or short-term goal |
Top 5 easy-access Cash ISAs
1. Trading 212 Cash ISA
- 5.40% AER variable, easy access, FSCS GBP 85K protected
- Flexible ISA feature (withdraw + redeposit within same tax year, no allowance use)
- 1.0% bonus for new customers in 2025 (some rate boosts)
- App-based, simple
- Trading 212 also offers Stocks ISA on same account
2. Chase Sapphire Cash ISA
- 5.30% AER, easy access
- Linked to Chase current account ecosystem
- App + web access
- No notice required for withdrawals
3. Marcus by Goldman Sachs
- 5.25% AER easy access (variable, can change)
- FSCS GBP 85K protected
- App + web; lump sum or direct debit deposits
- Bonus rate (~0.1%) for first 12 months ends, then ~5.15%
4. Nationwide Triple Access ISA
- 5.10% AER for 12 months (then rate drops to ~3-4%)
- Limit 3 withdrawals per year (else rate drops to standard ~2-3% for that year)
- For savers who plan minimal access
5. Coventry Building Society Easy Access ISA
- 5.10% AER
- Branch + post + phone access
- Local-friendly building society; long-standing top-tier rates
Mutual society + UK challenger banks dominate top-table. High-street banks (Barclays, HSBC, NatWest, Lloyds) typically offer 1.5-3.0% Cash ISA rates - far below top tables. Always shop the top tables.
| Provider | Rate (AER) | Access | Min deposit |
|---|---|---|---|
| Trading 212 | 5.40% | Easy / flexible | GBP 1 |
| Atom Bank 1-yr fix | 5.40% | No withdrawal | GBP 5,000 |
| Chase Sapphire | 5.30% | Easy | GBP 1 |
| Paragon 1-yr fix | 5.35% | No withdrawal | GBP 500 |
| Marcus by GS | 5.25% | Easy | GBP 1 |
Top 5 fixed-rate Cash ISAs
1. Atom Bank 1-year fixed
- 5.40% AER fixed for 12 months
- No withdrawals allowed (rate guaranteed)
- GBP 5,000 minimum deposit
- App-only bank
2. Paragon Bank 1-year fixed
- 5.35% AER fixed
- GBP 500 minimum
- No partial withdrawals; full closure with interest penalty if needed
3. Charter Savings Bank 2-year fixed
- 5.20% AER fixed for 24 months
- GBP 5,000 minimum
- Useful if expecting rates to fall (lock in the 2-year)
4. Tesco Bank 1-year fixed
- 5.20% AER fixed
- Lower minimum (GBP 200)
- Branch + phone access
5. Hampshire Trust Bank 2-year fixed
- 5.15% AER fixed for 24 months
- GBP 1 minimum (no real barrier)
- Smaller bank, FSCS GBP 85K protected
Ladder strategy: split your GBP 20K allowance across
- 1-year fix: GBP 6,667
- 2-year fix: GBP 6,667
- Easy access: GBP 6,667
If rates rise: easy access portion benefits, fixed locks are stable
If rates fall: fixed portions retain higher rates, easy access drops with market
This "barbell" strategy is the standard for cash management when rate path is uncertain.
FSCS protection + transfer rules
| Financial Services Compensation Scheme (FSCS) | Transferring ISAs | Transfer process |
|---|---|---|
| GBP 85,000 protection per authorized bank/society per depositor | Cash to Cash ISA: free, no contribution limit impact, no time on the market gap | Open the receiving ISA first (must accept transfers) |
| Combined accounts at the same authorization (e.g. Marcus + Goldman Sachs = same authorization) count together | Cash to Stocks ISA: same | Submit transfer request to NEW provider (NOT the old one) |
| Joint account: GBP 170,000 protected | Stocks to Stocks ISA: free (in-specie transfer of holdings) | New provider contacts old provider; transfer in 15 working days for Cash, 30 days for Stocks |
| Above GBP 85K: spread across different banks (each protected separately) | Lifetime ISA: from Cash LISA or Stocks LISA only, transfer to other LISA. Cannot transfer LISA to non-LISA without losing 25% penalty. | During transfer: balance moves between accounts; you do not "use" any new allowance |
| Junior ISA: separate rules; can transfer to adult ISA at 18 | Old ISA closes automatically |
DO NOT WITHDRAW the money yourself - that uses your allowance and you lose the ISA wrapper. Always use the formal "ISA transfer" process.
Multiple ISAs in same tax year (post-April 2024 reform)
- Can open multiple Cash ISAs at different providers
- Can open multiple Stocks ISAs at different providers
- Total contribution across all ISAs: GBP 20,000
- LISA still capped at GBP 4,000
- "Loyalty bonus" structures: some providers reset 12-month bonus if you transfer in
Before-April-2024 rule: only ONE active Cash ISA + ONE Stocks ISA per tax year. Reform abolished this restriction.
Common Cash ISA mistakes
- Putting savings in Cash ISA at the same rate as regular savings. PSA covers up to GBP 1,000/year for basic-rate taxpayer. Use regular high-interest first; ISA for the excess.
- Forgetting tax year resets April 6. Last-minute contributions in early April count for THIS tax year if made before April 5, NEXT year if April 6+.
- Confusing "fixed" with "long-term." Fixed-rate ISAs are typically 1-5 year terms. You can transfer them mid-term but with interest penalty (typically 90-180 days lost).
- Withdrawing then trying to redeposit. Most ISAs are NOT flexible. Once withdrawn, redepositing uses fresh allowance.
- Putting LISA money into Cash LISA "for safety." LISA bonus + Cash interest = ~6% effective; Stocks LISA (5+ year horizon) historically returns 7% + bonus = ~9% effective. Use Stocks LISA for 5+ year holds.
- Not transferring old high-fee Cash ISAs. Banks attract you with 5% bonus year then drop to 1-2%. Transfer to current top-table rate.
- Forgetting joint accounts not allowed. Cash ISAs are individual only. Married couple opens TWO accounts, each GBP 20K.
- Putting emergency fund in fixed-rate. If you need access during the term, you pay penalty. Use easy-access for true emergency money.
- Missing FSCS limit. Have over GBP 85K? Spread across separate banks (Marcus, Atom, Paragon, etc.) - separate FSCS authorizations.
- Hoarding cash in ISA when rates fall below mortgage rate. If you have a 5%+ mortgage and 4% Cash ISA, every pound in the ISA is costing you net interest. Pay down mortgage or invest in Stocks ISA.
Run the math for your situation
Use our GB calculator to plug in your own numbers.