Guides
A calculator gives you a number. These guides explain where it comes from - how the tax bands actually work, why a pay rise can cost you more than you'd expect, and which choices change the result.
I write each one myself and work every example through the site's calculators, so you can put in your own figures and follow along. They're split by country, because the rules really are different.
UK guides
- UK · Income tax Scottish income tax explained: the six bands and what they mean for your pay Scotland has six income tax bands to England's three. Here's how they work in 2026/27, who pays more and who pays less, and the pay range where the difference really bites. Read the guide
- UK · Income tax The £100k tax trap: why you keep so little of a pay rise above £100,000 Between £100,000 and £125,140 you lose your personal allowance, which pushes the real tax rate to 62% in England and 69.5% in Scotland. Here's how it works and what you can do about it. Read the guide
- UK · Pensions Salary sacrifice, net pay or relief at source: how your pension gets its tax relief The same pension contribution can cost you different amounts depending on how your employer runs the scheme. Here's how the three methods compare in 2026/27, in Scotland and the rest of the UK. Read the guide
- UK · Student loans UK student loan plans explained, and whether you should overpay Plans 1, 2, 4 and 5 and the Postgraduate Loan have different thresholds, interest rates and write-off dates. Here's how each works in 2026/27, and why overpaying is a bad idea for many graduates. Read the guide
- UK · Buying a home Stamp duty, LBTT and LTT compared: buying a home in England, Scotland or Wales The UK has three different taxes on buying a home, with different bands, first-time buyer rules and surcharges. Here's how they compare at typical prices, with worked examples. Read the guide
- UK · Self-employment How much to set aside for tax as a UK freelancer A practical guide to putting money aside for income tax and National Insurance when you're self-employed, including payments on account and the first-year January bill that catches so many people out. Read the guide
US guides
- US · Income tax How US tax brackets actually work: marginal and effective rates for 2026 Moving into a higher tax bracket never means taking home less. Here's how the 2026 federal brackets work, with worked examples, and why your effective rate is far lower than your bracket. Read the guide
- US · Pay Understanding your US paycheck: from gross pay to take-home Where the money goes between your salary and your bank account - federal withholding, Social Security, Medicare, 401(k), health premiums and state tax - with a worked biweekly example for 2026. Read the guide
- US · Self-employment US self-employment tax explained: what freelancers owe and how much to set aside Self-employed in the US? You pay both halves of Social Security and Medicare on top of income tax. Here's how self-employment tax works for 2026, the deductions that soften it, and a set-aside table by profit. Read the guide
- US · Mortgages How to get rid of PMI: the 80% and 78% rules, and how to get there sooner Private mortgage insurance doesn't have to last the life of your loan. Here's when US law says it must come off, how to ask for it to go earlier, and a worked example of the timeline on a $400,000 home. Read the guide