Dec 18th 2025

Article By GoSimpleTax
Whether you’re thinking about winding down this festive season or perhaps are busier than ever, the Self Assessment deadline is approaching. This means it’s never been a better time to look over your business and its numbers – and ensure it all stacks up.
One area that deserves your attention is allowable expenses. Why? Because research released by mobile business account ANNA Money found that the average self-employed individual leaves hundreds of pounds unclaimed every year – £840 to be exact.
What’s more, one in five of those surveyed complained they are simply not sure what they can and can’t claim. So, to avoid missing out on money that’s yours, keep reading to find out how you can make sure your records are complete and accurate before filing your return.
Instead of going head first into expenses and filing, it pays to gather the core documents that are required for your Self Assessment. This includes:
You’ll also need your Unique Taxpayer Reference (UTR) number and your HMRC sign-in details.
Lots of people underestimate their true business costs. Here’s a round-up of the most commonly forgotten expenses:
If you work from home, you may be entitled to claim:
You can also use HMRC’s flat-rate home-working allowance if it’s easier. And there are handy tools online to help you calculate what you could claim.
Unfortunately, commute costs to your regular workplace won’t count. But if you are travelling to a temporary or client location, it does.
These often get missed:
This includes:
When you see how many allowable expenses there are, you can understand why it’s so important to log every purchase made through your business throughout the year.
Next up, it’s time to run through your bank statements month-by-month. Ask yourself:
While many expenses are allowable, others are not. This includes:
In short, if an expense isn’t wholly and exclusively for your business, it likely won’t qualify.
While you could manually check your accounts for allowable and disallowed expenses, there is also software that does the job for you. In fact, it’s like having a digital tax assistant that ensures your return is accurate before you file, by flagging missing expenses, checking for errors and updating your tax owed in real time.
So, what are you waiting for? Leaving everything until the 31st January deadline makes self-employment more stressful than it needs to be. Run your tax health check today and file with confidence.
Income, Expenses and tax submission all in one.
GoSimpleTax will provide you with tips that could save you money on allowances and expenses you might have missed.
The software submits directly to HMRC and is the solution for freelancers, the self-employed, sole traders and anyone with income outside of PAYE to file their self-assessment giving hints and tips on savings along the way.
Get started with GoSimpleTax today, it’s free to try.
Speak to one of our friendly team members
0207 183 4775
09:00 – 17:30 | Monday to Friday
0207 183 2653
09:00 – 17:30 | Monday to Friday
0207 183 5369
09:00 – 17:30 | Monday to Friday