How HMRC calculates your self assessment tax bill: income tax at marginal rates, National Insurance for the self-employed, payments on account explained, and how to reduce your July bill.
Earn from tutoring, Etsy, Uber or dog walking? The £1,000 trading allowance may protect you — but above it, Self Assessment is mandatory. Here's every threshold, deadline and worked example.
If you sell on eBay, Vinted, Etsy or do gig work in the UK, the £1,000 trading allowance lets you earn up to £1,000 gross tax-free. Here's exactly how it works, when it applies, and the new platform reporting rules.
Self-employed Class 4 National Insurance fell to 6% on profits between £12,570 and £50,270 from April 2024 and stays there for 2025/26. Here's how it works, who pays, and worked examples on real profit figures.
Missing the 31 January Self Assessment deadline triggers an instant £100 penalty even if you owe no tax — then £10/day from day 90, plus 5% surcharges at 6 and 12 months. Late payment adds 7.75% interest in 2026. Full penalty schedule.
Voluntary National Insurance Class 2 costs £190 per year and Class 3 costs £957 per year — but they buy the same extra State Pension entitlement. Worked examples on the payback period and who qualifies for the cheaper Class 2 route in 2026/27.
Part 5 (final) of our Spring Budget 2026 series — Corporation Tax, dividend rates for owner-managers, R&D credits, IR35, Class 4 NI and what it all means for limited companies and sole traders.
Part 2 of our Spring Budget 2026 series — what the Chancellor announced for Class 1 employee NI, the 15% employer rate, Class 4 self-employed and the abolished Class 2. Worked examples included.
The Self Assessment online filing deadline is 31 January. Here's exactly who needs to file, the key dates, the penalty structure, and the things that catch first-time filers out.
