UK Financial Guides
Plain-English guides on ISA tax, saving, investing and retirement — each one built on transparent maths and official UK sources.
How much National Insurance do I pay?
Employees pay 0% up to £12,570, 8% up to £50,270 and 2% above — with worked examples for 2026/27.
Read article →How does inflation affect your money?
At 3% inflation, £1,000 today buys what ~£554 buys in 20 years. A plain-English UK inflation guide.
Read article →How is dividend tax calculated?
The first £500 of dividends is tax-free, then 10.75%, 35.75% or 39.35% depending on your income band — with worked examples for 2026/27.
Read article →How is capital gains tax calculated?
Your first £3,000 of gains is tax-free, then 18% or 24%. How CGT works for 2026/27, with shares, property and BADR examples.
Read article →ISA vs Pension
£200/month for 30 years: pension ~£176,855 after tax vs ISA £166,452. Tax relief vs flexibility.
Read article →Fixed vs variable mortgage
4.5% saves £69/month vs a 5% fix, but 6% costs £143/month more. How to choose the safe option.
Read article →Overpay mortgage or invest?
£200/month: overpaying saves £43,977 guaranteed vs investing at 7% could reach £162,014 (with risk).
Read article →Cash ISA vs Stocks & Shares ISA
£250/month: Cash ISA at 4% → £176,826 vs Stocks ISA at 7% → £313,109 over 30 years. Plus the 2027 rule change.
Read article →How much do mortgage overpayments save you?
£100 a month on a £180,000 @5% 25y loan saves ~£24,045 in interest and clears the mortgage almost 4 years sooner.
Read article →How much income tax will I pay?
UK tax bands for 2026/27 — the £12,570 Personal Allowance, the £100,000 taper, and what you actually pay from £50,000 to £200,000.
Read article →How much will my mortgage cost?
A £250,000 mortgage at 5% over 25 years costs about £1,461 a month — here is how your loan size, rate and term change the bill.
Read article →Are ISAs tax-free? How UK ISA tax works
How an ISA shelters your interest, dividends and gains from UK income tax, dividend tax and capital gains tax in 2026/27.
Read article →How much will £500 a month grow in 20 years?
You put in £120,000. At 4–8% growth that could become £183k to £295k — here's the full maths and what inflation does.
Read article →How does the LISA 25% bonus work?
Pay £4,000 into a Lifetime ISA and the government adds £1,000 a year. Rules, eligibility and the 25% penalty to avoid.
Read article →How much Stamp Duty will I pay in 2026/27?
England, Scotland and Wales compared — a £350,000 home costs £7,500, £8,350 or £7,500 depending where you buy. First-time buyer relief explained.
Read article →How much do I need to retire with the State Pension?
The full State Pension is £12,548 a year. To retire on £25,000 you'd need roughly a £311,000 pot on top — the 4% rule worked out.
Read article →Rent vs buy: should I buy a home in the UK?
Deposit, stamp duty, mortgage interest and maintenance vs rent and investment returns — the break-even years and what actually matters.
Read article →UK tax codes explained: what does 1257L mean?
How your PAYE tax code is built — the numbers, the letters (L, M, N, BR, D0, D1, S, NT, K), and what to do if yours is wrong.
Read article →Offset mortgage explained: is it worth it?
How linking your savings to your mortgage cuts interest — the maths, the trade-offs, and who benefits most from an offset deal.
Read article →Take-home pay breakdown: where your salary goes
Gross to net in 2026/27 — Income Tax, National Insurance, pension and student loan. Examples from £30,000 to £100,000.
Read article →Child Benefit 60% trap: the HICBC explained
Earn over £60,000 and claim Child Benefit? The charge claws it back by £80,000 — and can push your marginal rate toward 60%.
Read article →Want a topic covered? Email Casvia.