Tax learning hub · 36 lessons
Understand your payslip, your tax and your money
Plain-English lessons for employees, freelancers, investors and expats. Whether you're in London, Lagos, Lisbon or LA — the fundamentals of how income tax works are the same.
The basics
Start here. The core mechanics behind every payslip in the world.
Employment income
Everything about wages, bonuses, benefits and equity compensation.
Self-employed & freelance
Sole traders, contractors and side-hustlers.
Investing & capital gains
Shares, funds, crypto, and the shelters that keep them tax-efficient.
Property & rentals
Buying, selling and letting property.
Life events
Marriage, kids, divorce, inheritance and moving abroad.
Year-end planning
Moves to make before the tax year closes.
Glossary
The tax vocabulary you'll bump into everywhere.
- Gross pay
- Total earnings before any tax or deductions.
- Net pay
- What lands in your bank account — gross minus tax, social and deductions.
- Taxable income
- The amount your tax is actually calculated on, after allowances and deductions.
- Tax bracket
- An income range taxed at a specific rate. Only income within the bracket is taxed at that rate.
- Marginal rate
- The rate applied to your next unit of income — the rate of your top bracket.
- Effective rate
- Total tax paid divided by total income — always lower than the marginal rate.
- Withholding
- Tax your employer deducts and remits to the tax authority on your behalf.
- Allowance
- An amount of income that isn't taxed.
- Deduction
- An amount subtracted from income before tax is calculated.
- Credit
- An amount subtracted directly from the tax you owe — pound-for-pound.
- Refundable credit
- A credit that pays out even if it exceeds your tax bill.
- PAYE
- Pay As You Earn — the UK system for employers to deduct tax from wages.
- Self Assessment
- The UK's annual tax return for self-employed, landlords and high earners.
- 1099 / W-2
- US information forms — W-2 for employees, 1099 for contractors.
- Cost basis
- What you paid for an asset — used to compute capital gain on sale.
- Capital gain
- Profit made on selling an asset for more than you paid.
- Salary sacrifice
- Giving up gross salary in exchange for a benefit (pension, EV, cycle) — saves both tax and NI.
- P60 / P45
- UK end-of-year pay summary / leaving statement.
- Refund
- Money returned when you overpaid tax during the year.
- Double taxation treaty
- Agreement between countries to prevent the same income being taxed twice.
Educational only. Figures and thresholds are for the current or recent tax year and change frequently. Always verify with the official revenue authority or a qualified adviser before acting on tax decisions.