Best Cash ISAs UK 2026/27
Independent comparison of UK Cash ISAs — easy access, fixed rate, flexible and beginner picks. Updated for 2026/27.
Pennywise Finance is a small, independent site of straightforward calculators and plain-English guides — built to help you see exactly where your pounds are going and what they could become.
Every tool runs entirely in your browser — nothing you type leaves your device, and no sign-up is needed. Use them as many times as you like.
Work out your net salary after income tax, NI, pension and student loan. 2026/27 UK tax year.
Open calculator →See what a regular savings habit grows into with compound interest, including monthly top-ups.
Open calculator →Find out how much interest you'd save and how many years you'd shave off by overpaying.
Open calculator →Work out monthly payments, total interest and a full month-by-month amortisation table.
Open calculator →Allocate your £20,000 ISA allowance across Cash, Stocks & Shares and Lifetime ISAs.
Open calculator →Interactive guide to the factors that move your UK credit score, and how much each one matters.
Open guide →Pension calculator, retirement drawdown, salary & tax calculator. Tell us what to build next.
Suggest a tool →Independent comparison of UK Cash ISAs — easy access, fixed rate, flexible and beginner picks. Updated for 2026/27.
£1,000 of tax-free interest a year for basic-rate taxpayers — but the rules change quickly once you cross into higher-rate territory.
The maths question that splits financial Twitter every quarter, worked through with realistic 2026 numbers.
The honest "depends on your time horizon" answer with the actual UK return data behind it.
Three months? Six? In an ISA, Premium Bonds, or instant-access? A practical, ranked guide.
A practical week-by-week plan covering the actions that move the dial — and the ones that don't.
Free £1,000 a year sounds great. The penalty rules and £450k cap have shifted the maths since 2024.
Pennywise Finance started as a personal collection of money spreadsheets — the kind you build to talk yourself out of a daft purchase or to check whether overpaying the mortgage really beats topping up the ISA.
We've turned the most useful ones into clean, mobile-friendly calculators. They're free to use, advert-supported, and never ask for your name, email or bank details. Read more on the about page.
Pennywise Finance provides general information only. We are not a regulated financial adviser.
Calculators are educational tools. Always check the figures with your provider and, for big decisions, consider speaking to a qualified adviser or MoneyHelper.
Our most-used provider comparisons across ISAs, pensions and mortgages — updated for the current UK tax year.
Moneybox, Nutmeg, AJ Bell and Dodl compared. 25% government bonus on contributions.
Open comparison →Trading 212, InvestEngine, AJ Bell and Hargreaves Lansdown compared.
Open comparison →PensionBee, AJ Bell, HL and Interactive Investor compared for consolidation and DIY.
Open comparison →Habito, Tembo, L&C and Mojo compared. Free, whole-of-market UK brokers.
Open comparison →Client-side UK personal finance calculators — your inputs stay on your device.
Project your pot and sustainable withdrawal rate.
Open calculator →FTB, home mover and additional property bands.
Open calculator →Interest saved and years off your term.
Open calculator →The true cost of an early Lifetime ISA withdrawal.
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