Sole trader tax blog (2026/27)

Articles on sole trader tax, Self Assessment, expenses, NI and tax planning for self-employed people in the UK.

The blog is where we write longer, single-topic articles for the 2026/27 tax year. Each one walks through a subject from start to finish with a worked example; the guides are organised for finding one answer quickly.

Each article is reviewed against GOV.UK and HMRC guidance after every Budget and updated in place when a figure it relies on changes, so the 2026/27 numbers you see are the current ones.

For a quick answer to one question, the guides are grouped by topic, and the calculator works out your own figures.

May 2026 · 6 min read

Sole Trader Tax Explained 2026/27: Income Tax, Class 2 and Class 4 NI

Start here if you are new to self-employment. It follows £40,000 of profit through Income Tax and Class 4 National Insurance step by step, and explains why Class 2 no longer appears on most bills.

Read article →

May 2026 · 5 min read

Self Assessment Deadlines and Penalties 2026/27: What You Need to Know

Every date in the Self Assessment year in one place, then what each missed deadline costs, from the £100 late filing penalty upwards, and how an appeal works.

Read article →

June 2026 · 7 min read

Sole Trader vs Limited Company: A Tax Comparison for 2026/27

Runs the same profit through both structures at £30,000 and £60,000, counting corporation tax, dividend tax and accountancy costs, to show when a company is and is not worth it.

Read article →

June 2026 · 6 min read

Allowable Expenses for Sole Traders 2026/27: What You Can Claim and What You Cannot

The flat rates for mileage and home working side by side with actual costs, then how the wholly and exclusively rule applies to a home office, a car, a phone and software.

Read article →

August 2026 · 7 min read

Making Tax Digital for Income Tax: The 2026 Guide for Sole Traders

What Making Tax Digital changes day to day: who joined in April 2026 and who joins next, the four quarterly deadlines, choosing software, and how the new penalty points work.

Read article →

Start from your question

How much tax will I pay? Sole trader tax calculator and how to work out your profit first. Enter profit, not turnover; the guide shows how to get from one to the other.
I have a job as well. What does the side business cost? Employed and self-employed calculator. Your salary uses the allowance first, so the profit is taxed at your top rate; Class 4 depends on the profit alone.
What do I pay on 31 January? Your tax bill and payment plan and payments on account. The first year with a bill of £1,000 or more asks for half as much again.
Is my State Pension year covered? Self-employed NI calculator. From £7,105 of profit the year counts automatically; below that, voluntary Class 2 is £3.65 a week.
Should I pay into a pension? Pension tax relief for sole traders. The provider adds 20%, higher-rate relief comes off your bill, and Class 4 is not reduced.

Added and rewritten recently

How to work out your self-employed profit (7 November 2026): Turnover to net profit to taxable profit, with a decorator's year and what £1,000 of expenses saves.
Pension tax relief for sole traders (7 November 2026): Relief at four levels of profit, including the 60% slice between £100,000 and £125,140.
Self-employed NI calculator (rewritten 7 November 2026): Class 4 against employee NI, partners, and whether a voluntary Class 2 year is worth £189.80.
Employed and self-employed calculator (rewritten 7 November 2026): The 80% payments-on-account test, paying through your tax code and a student loan on side income.
Budget 2026 for sole traders (29 October 2026): The trading allowance rising to £3,000 from April 2027 and what else the Budget left alone.

This page last reviewed 7 November 2026. Calculators checked against GOV.UK rules on 3 November 2026.