The deadline for filing your 2025 tax return is fast approaching. If you already work with a specialist accountant then no doubt they’ve already done this for you, but if you’re a sole trader or small business that is still managing its own Self Assessment you might be looking for some tips to make sure you do it right.
The deadline for submitting your tax return is 11.59pm on Friday 31st January 2025, but before we offer our 6 tips, let’s see if you actually need to file a tax return at all.
Who needs to submit a Self Assessment tax return?
Sole traders and partners in a business, or anyone that receives other forms of taxed income through investments, will likely have to submit a Self Assessment tax return. This applies to landlords too, but if you’re not sure whether or not you should be filing a tax return you can use HMRC’s Self Assessment Checker tool.
6 tips for filing your 2025 tax return
If you haven’t filed your tax return for 2025 yet, here are 6 tips for getting it right. Finding this article ahead of filing your 2026 tax return? Don’t worry—many of these tips still apply.
- Have all of the necessary documentation to hand
- File Online
- Remember, your balance will take a few days to update
- Think ahead to next year
- Get ready for Making Tax Digital (MTD)
- Seek professional advice
Have all of the necessary documentation to hand
Submitting your 2025 tax return will take much longer if you don’t gather all of your documentation first. This includes all records of your income and expenditure, National Insurance number, PAYE and VAT records (if applicable), details of your pension and charity contributions and the Unique Taxpayer Reference (UTR) which you should have received when you registered for Self Assessment.
If you were also employed for all or part of the 2023/24 tax year you will need details of what you earned and the tax you already paid. HMRC might have this on record automatically, but if not you’ll need your 2023/24 P60.
File Online
Submitting your tax return online is the fastest and easiest way of doing so. However, the deadline for registering for the first time is 5th October, so you will need to have done this already.
When submitting your tax return online it’s not only easy to upload all of your necessary documentation, but you can save it as you go, meaning you don’t have to do it all at once.
Remember, your balance will take a few days to update
When you first submit your tax return a screen will show an estimate of what you owe for the 2023/24 tax year. You can choose to pay your tax bill on the same day as you file the return, but the amount you’re due to pay before 11.59pm on 31st January will take up to 72 hours to calculate within the Self Assessment portal.
The initial estimate will also include your ‘Payments on Account’ for 2024/25 which are payments towards your next tax bill to help you spread the cost across two payments. Payments on Account are due by 31st July 2025, and will be calculated based on what you earned in the 2023/24 tax year, although you can request to reduce this amount if you anticipate earning less self-employed income during this tax year.
After filing your tax return, keep logging back into the Self Assessment portal over the following three days to see if your balance has been updated with the amount of tax you’re due to pay before 11.59pm on 31st January. This final figure will take into account any tax paid as part of employment during the 2023/24 tax year, as well as your Payments on Account made in July 2024 (if this isn’t your first time filing a return).
Think ahead to next year
Submitting a Self Assessment tax return for the first time can be a little overwhelming, and it’s also going to be the return that takes you the longest to complete. However, it still pays to think ahead to the following year.
First of all, make sure you remember that you’ll be due to pay your Payments on Account by 11.59pm on 31st July. Your tax return calculation will let you know how much this is going to be, so make sure you’ve got it when the deadline comes around.
It’s also worth considering submitting your 2024/25 tax return early. You can do so as soon as the tax year ends (5th April 2025), and therefore avoid rushing to get it submitted by 31st January 2026.
Get ready for Making Tax Digital (MTD)
Making Tax Digital (MTD) requires businesses over the VAT threshold to keep digital accounting records and submit their VAT returns online using an MTD-compliant cloud bookkeeping solution.
MTD will apply to all unincorporated businesses and landlords with annual business or property income over £50,000 from April 2026, and from April 2027 for those with an income above £30,000 per year—but you don’t have to wait to get ahead of the game.
Self-employed businesses and landlords can check if they’re able to voluntarily sign up now through their accountancy software provider.
Seek professional advice
The easiest way to ensure your Self Assessment tax returns are filed properly every year? Seek the support of an experienced accountant for sole traders and small businesses.
Here at Warr & Co we’ve got decades of experience in helping individuals and small businesses manage and optimise their tax affairs, while we’ve also partnered with the leading cloud-based bookkeeping services, allowing you to get started with Making Tax Digital right away.
So, if you want to stop worrying about the Self Assessment deadline every January and focus on what you do best, get in touch with our friendly and professional team today. We even offer free, no obligation Self Assessment consultations where we’ll get to know your current situation and whether or not we can help.