10 self assessment mistakes sole traders make every January (and how to avoid them)
Common errors sole traders make at tax return time, from payments on account shocks and late payment penalties to MTD changes in 2026. Be prepared!
Tax & HMRC
Understanding how tax works is essential when you’re self-employed.
This section explains how the UK tax system applies to sole traders, including Income Tax, National Insurance, Self Assessment and VAT.
You’ll also find guidance on registering with HMRC, claiming allowances, meeting tax deadlines and preparing for Making Tax Digital.
Whether you’re starting out or checking that your tax affairs are in order, these guides explain the rules in plain English.
Start with these guides
Self Assessment and tax returns
Tax mistakes and common problems
Registering with HMRC
National Insurance and allowances
VAT and business taxes
How to register as self-employed with HMRC – the key steps
You’re self-employed if you work for yourself and aren’t paid through PAYE. If you earn more than £1,000 a year this way, you need to register with HMRC.
Small company owners hit hard by April 2026 dividend tax increase
In today’s Autumn Budget, the Chancellor confirmed that the basic and higher rates of dividend tax will rise by two percentage points from April 2026.
HMRC reminds Christmas side hustlers to check if they need to pay tax
HMRC has issued a festive reminder to anyone making extra money from market stalls and other seasonal side hustles, to check if their earnings are taxable.
How do student loan repayments work if you’re a sole trader?
How do student loan repayments work when you’re self-employed?. Find out how HMRC calculates what you owe, and how much you’ll repay via Self Assessment.
31st October paper Self Assessment deadline: who it applies to
The paper Self Assessment deadline is 31st October. Find out who can still file on paper, what happens if you’re late, and how to avoid HMRC penalties.
What to do if you accidentally register twice with HMRC as a sole trader
Accidentally registered twice as a sole trader with HMRC? Learn how to fix duplicate UTRs, avoid penalties, and get your Self Assessment record corrected.
What is the October 5th Self Assessment deadline and what happens if you miss it?
If you became self employed during the previous tax year, make sure you register for Self Assessment by 5th October to avoid HMRC penalties. What happens if you miss this deadline?
UTR number explained – what it is, when you need one, and how to get it
A Unique Taxpayer Reference (UTR) is a 10-digit code from HMRC used for tax. Find out when you get one, why it matters, and how to register or recover it.
High Income Child Benefit Charge – what self-employed people need to know
Guide to the High Income Child Benefit Charge for self-employed parents. How it works, who it affects, deadlines, NI credits, and planned 2026 changes.