Let’s face it – few things strike fear into the heart of the self-employed quite like the words ‘Self-Assessment’.
But it doesn’t have to be stressful. With a little preparation, a clear plan, and the right support, filing your return can be quick, painless, and even save you money.
The team at JF Hornby & Co have put together a handy guide with everything you need to get it right – from key deadlines to smart record-keeping and the common traps to avoid.
And remember – if it’s all too much, our friendly team are here to take the pain away.
Key dates you need to know
31 October – Deadline for paper tax returns.
31 January – Deadline for online tax returns and payment of any tax owed.
31 July – Second payment on account (if applicable).
Hornby Tip: Don’t wait until January. HMRC’s system has a habit of slowing to a crawl under the weight of last-minute filers.
Who needs to complete a Self-Assessment?
You will need to join the self-assessment party if you:
Are self-employed or a partner in a business
Are a company director (unless all income is taxed via PAYE)
Have rental income, dividends, or foreign earnings
Earn over £100,000 a year
Claim child benefit and your income is over £50,000
If in doubt, ask your accountant – they’ll tell you straight away whether you’re in the firing line.
What you’ll need before you start
Your UTR (Unique Taxpayer Reference)
Your National Insurance number
P60 or P45 (if employed during the year)
Records of self-employed income and expenses
Details of bank interest, dividends, and investments
Charitable donations or pension contributions
Any rental income and expenses
Image: Nataliya Vaitkevich
Top Tips for a smooth submission
Keep good records all year – use apps or accounting software if you can.
Set aside tax money monthly – roughly 20–30% of your profits.
Double-check expenses – don’t miss claimable costs like home office use, travel, or professional fees.
File early – the earlier you submit, the sooner you’ll know what you owe (and avoid nasty surprises).
Use an accountant — they’ll spot reliefs you might miss and make sure you stay compliant.
Common pitfalls to avoid
Mixing personal and business bank accounts.
Forgetting about student loan repayments.
Missing payments on account.
Overlooking income from side hustles or online platforms.
Ignoring the January panic until it’s too late.
How the team at JF Hornby & Co can Help
Make sure every allowance and relief is used.
Help plan for next year’s tax bill.
Identify ways to save money legitimately.
Take the stress out of deadlines.
Need a Hand?
If you’re unsure where to start, talk to our team. We’ll make sure your return is filed correctly, on time, and without unnecessary stress – leaving you to get on with running your business.
Call 01229 588 077 or email jfh@jfhornby.com
