Welcome to our first blog of 2026!
With the Self Assessment tax return deadline fast approaching (midnight on 31 January), many UK business owners and sole traders find this time of year stressful. Each January, we speak to clients who feel rushed, overwhelmed, or unsure whether they’ve got everything they need to submit on time.
The good news? With a bit of organisation and the right support, filing your tax return doesn’t have to be a dreaded task.
Below, we’ve pulled together practical reminders, an easy checklist, and advice on how to make the process smoother, all while avoiding unnecessary penalties.
Who Needs to Complete a Self-Assessment Tax Return?
Your obligation to file depends on specific income types and whether they’re untaxed, not just total earnings. You should file if you have untaxed income such as rental profits, dividends, savings interest, foreign income, or other untaxed earnings.
You’ll also need to submit a Self-Assessment tax return if you:
- Are self-employed or a sole trader
- Are a company director
If you’re unsure whether Self-Assessment applies to you, it’s important to check as early as possible. Leaving it too late can cause delays and added pressure.
First-time filers:
If this is your first Self-Assessment, you must have registered with HMRC by 5 October 2025 to receive your Unique Taxpayer Reference (UTR) in time to file by 31 January 2026.
Start Early
If your tax return is still on your to-do list, now is the time to act. Leaving everything until the final days of January can increase stress and the risk of mistakes.
Even if that just means gathering paperwork, starting now gives you breathing space. It also allows time to ask questions, correct errors, or seek support if needed.
Please note, if your tax bill is over £1,000 and not mostly collected at source, you may need to make payments on account for the next year: due 31 January and 31 July.
Remember, if you file late you’ll get a £100 fixed penalty. After 3 months you can be charged £10 per day (up to £900), with additional penalties at 6 and 12 months. Separate penalties also apply if you pay tax late, for example 5% of unpaid tax at 30 days, 6 months, and 12 months.
Little and Often: Organisation Makes a Difference
One of the biggest challenges with Self-Assessment is paperwork. Receipts, invoices, bank statements, and income records can quickly pile up.
A helpful approach is to organise documents little and often:
- Set aside regular time to sort paperwork
- Use calendar reminders so it doesn’t get forgotten
- Keep digital copies of receipts where possible
This reduces the chance of missing information and avoids the stress of trying to organise everything at the last minute.
Create a Filing System That Works for You
There’s no one-size-fits-all approach, so the best filing system is just the one you’ll actually use.
That might be:
- Digital folders on your computer or cloud storage
- A simple spreadsheet to track income and expenses
- Accounting software or apps
- Physical folders or document wallets
If you’re out and about, keeping a document wallet for receipts can save time and frustration later. The goal is consistency, not perfection.
A Simple Self-Assessment Checklist
Before you sit down to file your return, make sure you have:
✔ Government Gateway login details
✔ Records of all income (invoices, payslips, rental income, dividends)
✔ Business expenses and receipts
✔ Bank statements
✔ Details of pension contributions or charitable donations
✔ Your previous tax return (useful for reference)
✔ Your Unique Taxpayer Reference (UTR), issued when you register for Self-Assessment.
Having everything in one place makes the process quicker and far less stressful.
Don’t Let It Become Overwhelming
Self-Assessment can feel daunting, especially if you’re busy running a business. But it doesn’t have to be done alone.
If you’re unsure about anything, seeking professional advice early can prevent problems later. And if organisation is the main issue, having practical support can make a real difference.
How MOMENTUM Can Help
At MOMENTUM, we support UK SMEs and business owners with the difficult, practical parts of running a business, including help during the Self-Assessment season.
We can help by:
- Organising and preparing financial information
- Supporting the filing process
- Reducing errors and avoiding penalties
- Taking the pressure off during a busy January
Our aim is to make the process clearer, calmer, and easier, so you can focus on your business.
Final Reminder
The online Self-Assessment deadline is midnight on 31 January. If your return is still outstanding, now is the time to take action.
You can find official guidance on completing your Self-Assessment tax return on the GOV.UK website – https://www.gov.uk/browse/tax/self-assessment.
If you’d like support with organisation or preparation this year, get in touch with MOMENTUM today, we’d love to hear from you to help you meet the deadline with confidence.
make it happen..
T: 01903 910546 or E: makeithappen@mbsmih.com