sole trader taxes

Tax Calendar 101: Stay Ahead of the Game with Key Dates for Sole Traders

Going self-employed is a major milestone in anyone’s career, and there’s a whole lot to think about before you make the leap. Aside from setting up and running the business itself, you’ll have an array of other responsibilities to consider… responsibilities like paying your taxes on time.

Whether you plan to hire an accountant or handle your finances yourself, it’s vitally important that you’re aware of the key financial dates for self-assessment. To help make your life a little easier, we’ve rounded up a list of all of the essential dates you need to know about.

What Happens If You Miss an HMRC Deadline?

Before we get to those all-important deadlines, though, let’s delve a little deeper into the importance of meeting them.

If you complete your self-assessment late, you’ll automatically be fined £100 – whether you owe any tax or not. This applies even if you miss the deadline by just a few hours: if you’re late, you can expect a fine.

Being a day or two late is one thing, but what happens if you miss the end of the tax year entirely? Fail to file your tax return before the end of April and you could face a fine of up to £1,000 – and you’ll also be liable to pay interest on the value of any tax you still owe.

Self-Assessment Deadlines and Key Dates for Self-Employed Workers

Looking for a list of key HMRC dates for 2024? We’ve got you covered.


The 31st of January is the deadline for making your first payment on account (an advanced payment) towards your tax bill for the financial year ending the following the 5th of April. In the case of the 2023/24 tax year, this payment must be made by the 31st of January 2024.

There are a couple of January deadlines which apply to the previous tax year, too. All online tax returns must be submitted by the 31st of January to avoid further penalties – even if you don’t owe any tax. This date is also the cutoff for paying your remaining tax balance. Any tax you still owe HMRC must be paid by the 31st of January following the previous tax year.

Need to make an amendment to a previous tax return? You’ll have another year to notify HMRC of any changes that need to be made. The deadline for informing them of any inaccuracies is the following 31st of January. In other words, if your 2023/24 return was incorrect, you’d have until the 31st of January 2026 to let HMRC know, regardless of whether you submitted it online or on paper.


The 5th of April marks the end of the current tax year, making it a significant date for all self-employed Brits. Once the tax year ends, you’ll be sent a letter reminding you to file your tax return. This applies even if you ceased trading during the previous financial year.

Those new to self-employment won’t automatically receive a reminder to file their tax return. In order to get one, you’ll first need to register your self-employed status with HMRC.


A few months after the tax year ends, another deadline looms. The 31st of July marks the deadline for submitting your second payment on account for the tax year that ended in April.


If you’ve generated income that hasn’t yet been taxed or capital gains above the current threshold (£6,000 for the 2023/24 tax year), you’ll need to notify HMRC of this by the 5th of October. They will then be able to issue you with a tax return notice.

The 5th of October is also a crucial deadline for the newly self-employed. You have until this date to notify HMRC of your new employment status using a CWF1 form.

October is a particularly important month, as the 31st is also the cut-off date for filing a paper tax return for the previous tax year (which ended in April).


Planning to file your tax returns online? You’ll need to do it before the 30th of December in order to avoid a fine. Once again, this applies to the tax year which ended the previous April.

How Stonehouse Can Help

We hope the guide above helped demystify those vital HMRC self-assessment deadlines. But if you have any questions or want to enlist the services of a professional accountant, our team is here to help.

We can help you navigate the ins and outs of sole trader tax with our tailored accounting services. Our highly-qualified team of accountants can complete HMRC self-assessment tax returns on your behalf, saving you time and hassle. Let us take care of your tax obligations so you can get back to doing what you do best: running your business.

Interested? Speak to our Peterborough-based accountants today to find out more.