Self Assessment mistakes are rarely about complicated tax rules. They’re usually caused by missed deadlines, forgotten income, incorrect expenses, or last-minute rushing. This practical guide breaks down the most common Self Assessment errors UK taxpayers make, explains what they cost, and shows you exactly how to avoid them.

Understanding which expenses you can claim as a sole trader is one of the simplest ways to reduce your tax bill. This guide breaks down the rules on allowable expenses, capital allowances, home office costs, and mileage so you can confidently claim every deduction you're entitled to — and avoid paying more tax than you need to.

Everything you need to know about tracking sole trader expenses from setting up systems and tools to common pitfalls to avoid.