The best cash ISAs with the biggest interest rates in 2026
Financial Interest was founded by Damien Talks Money (407,000 YouTube subscribers) to teach the personal finance lessons he wished he'd been taught at school.
Last updated 1st July 2026
6 min read
The highest interest rates
| Provider | Interest rate** | Fi score | Notes | Minimum balance*** | Maximum withdrawals*** |
|---|---|---|---|---|---|
| Tembo* | 4.05% | 4.4 | Includes bonus rate for the first year. ISA transfers get 4.00%. | £10 | Unlimited |
| Trading 212* | 4.51% | 4.3 | Includes bonus rate for first year, though ISA transfers contributed outside of current tax year only get 3.60% AER (variable). | £1 | Unlimited |
| Plum* | 4.62% | 4.3 | Includes bonus rate for first year, ISA transfers only get 4.00% AER (variable). | £1 | Unlimited |
| Cynergy Bank | 4.15% | 4.2 | No limited time promotional periods or reduced rates on transfers. | £1 | Unlimited |
| Marcus by Goldman Sachs | 4.01% | 3.7 | Includes bonus rate for the first year. | £1 | Unlimited |
**AER (variable) for easy access cash ISAs, rates accurate as of 1st July 2026.
***Minimum balance and maximum withdrawals to maintain the advertised interest rate.
What is Fi score?
This is our in-house rating, built by Financial Interest’s expert review team. It takes into account fees, features, and usability for each account type, then combines these into an overall score for the platform as a whole.
List includes easy access cash ISAs only – variable rate, no fixed terms. All rates were accurate as of 1st July 2026. Rates change quickly and may be different to what you see on this page. Get in touch if you'd like to report a mistake.
Financial Interest provides guidance, not advice. If you’re unsure about anything, speak with a qualified adviser. When investing, your capital is always at risk. Past performance does not guarantee future results.
The four best easy access cash ISAs for interest rates in the UK, at the time of writing, are Tembo, Trading 212, Plum, Cynergy Bank, and Marcus by Goldman Sachs.
But due to limited-time promotional rates, it takes a bit of digging to work out which rates are really the highest and which platform offers the best cash ISA all-round.
Please remember, all rates on this page are variable (AER).
Tembo has the top-ranked cash ISA by Fi Score – they offer a decent promo rate of 4.05%, a 4.00% interest rate on ISA transfers, a low minimum deposit, and they don't reduce your rate if you withdraw too many times. Plus, there's the option to open a "no bonus" cash ISA with a 4.00% rate, so you don't have to worry about it dropping after 12 months.
Close up behind is Trading 212 with a promotional rate of 4.51%. Their ISA is flexible – where you can withdraw and redeposit in the same financial year without affecting your annual ISA deposit limits. This includes a promotional rate that is removed after 12 months.
This boosted rate is available via our link on Financial Interest, or by using the promo code FIN, as a new customer. It only applies to new deposits, or ISA transfers on contributions made within the same tax year.
Next is Plum – new customers get 4.62%, while ISA transfers get 4.00%. However, after a year, your rate will drop to 2.54%.
Cynergy Bank offers a slightly lower rate of 4.15%, but the rate doesn't drop after a promotional period, allows unlimited withdrawals, and applies to ISA transfers.
Marcus by Goldman Sachs offers a decent 4.01% rate which includes a bonus for the first year, after which your rate will drop to 3.27%. ISA transfers are accepted, and a low minimum deposit of just £1 is required.
Trading 212's cash ISA is flexible, as is Plum's, meaning you can withdraw your money from your ISA and pay it back without it affecting your allowance. The other leading options are not flexible.
List includes ISAs that are either easy access or allow at least three withdrawals – variable rate, no fixed terms. All rates were accurate at the time of publishing. Rates change quickly and may be different to what you see on this page. Get in touch if you'd like to report a mistake.
Promo code worth up to £100 with Trading 212
Get free fractional shares worth up to £100 when you join Trading 212 and deposit at least £1 via our link, or use promo code FIN within your account. Terms apply. Affiliate link.
Free share worth £10-£100 with Freetrade
Claim a free share worth between £10-£100 when joining Freetrade. Minimum deposit £50. Terms apply. Affiliate link.
Free fractional shares worth up to £100 with Lightyear
Get up to £100 in free fractional shares when joining Lightyear via our link, or using promo code ‘FIN’. Minimum deposit £100. T&Cs apply. Affiliate link.
Reasonable rates
| Provider | Easy access interest rate (July 2026)** |
|---|---|
| XTB | 4% |
| eToro | 3.87% |
| MoneyBox | 3.80% |
| Nottingham Building Society | 3.80% |
| Lightyear* | 3.75% |
| Monument | 3.74% |
| CMC Invest | 3.69% |
| Prosper | 3.61% |
| Zopa | 3.25% |
**AER (variable) for easy access cash ISAs, rates accurate as of 1st July 2026
***Minimum balance required and maximum withdrawals to maintain the advertised interest rate.
Very low rates and the worst offenders
| Provider | Easy access interest rate (July 2026)** |
|---|---|
| Aldermore | 2.25% |
| Coventry Building Society | 2.00% |
| HSBC | 2.50% |
| Leeds Building Society | 1.45% |
| Paragon | 1.50% |
| Royal Bank of Scotland | 1.15% |
| NatWest | 1.15% |
| TSB | 1.10% |
| Santander | 2.00% |
| Barclays | 1.00% |
| Lloyds Bank | 1.00% |
| Bank of Scotland | 1.00% |
| Metro Bank | 0.90% |
***Minimum balance required and maximum withdrawals to maintain the advertised interest rate.
Some of these banks are making so much margin on their savings accounts that the FCA is actively encouraging them to be provide better value for customers.
The rates are frankly laughable.
As a standout example, Metro Bank recently dropped their rate to 0.9% in response to the Bank of England changing the base rate.
We're not sure anyone offering 1% was in need of a "response" to the Bank of England's base rate decrease, but hey, we're just some Average Joes sharing our unqualified thoughts about money on the internet.
