What Happens If I Miss The Deadline To Submit My Tax Return Form?

Tax return submission deadlines are there for a reason. HMRC need to collate all the necessary taxpayer information by a certain date so the government can determine its financial budget for the year ahead. Anyone who…

10 Minute Read

Last Updated: 8th February 2022

Tax return submission deadlines are there for a reason. HMRC need to collate all the necessary taxpayer information by a certain date so the government can determine its financial budget for the year ahead.

Anyone who doesn’t submit their tax return on time causes HMRC a real headache – which is why there are ramifications awaiting late taxpayers. When it comes to the Self Assessment tax return deadline, the taxman doesn’t mess about…

So, what happens if I miss the deadline to submit my tax return form?

If you fail to hand over your forms to HMRC before the Self Assessment tax return deadline, you’ll receive an immediate penalty of £100. But you can’t simply take the fine on the chin and assure the taxman it won’t happen again. HMRC will continue you to hit you with further penalties until you finally submit your tax return.

Online tax forms received later than midnight on 31st January (or 31st October for paper returns) face the initial £100 penalty, with an additional £10 fine added every day after three months have passed (30th April or 31st January, respectively) for the next 90 days (up to a maximum of £900).

If your tax return is six months late, you’ll be forced to pay a £300 penalty or 5% of the total tax due (whichever is greater). If you wait a whole year before submitting, another £300 fine comes your way (or 5% of the total tax due – again, depending on which is higher).

For submissions more than a year late, you may be asked to pay 100% of your tax return… essentially doubling your liabilities.

How do I avoid missing the tax return deadline?

Many people will tell you, quite unhelpfully, that there’s no excuse for missing the tax return deadline, and that you simply need to get these forms in on time. Unfortunately, HMRC share this mindset. But, as you’ll know, it’s tough to prioritise tax when you’re a busy entrepreneur. That’s why you should take the necessary steps to make things easier for yourself.

Minimise paperwork by migrating all your tax documents online. This lets you access and update files on the go from almost anywhere in the world. For the paperwork you do need to keep hold of (receipts, invoices, proof of address), be sure to purchase a paper tray or folder to keep them organised and avoid sifting through lots of documents when you next need to find something in particular.

But the foolproof solution for filing on time is taking advantage of tax software like SimpleTax. Every year, thousands of newly self-employed workers ask “what happens if I miss the deadline to submit my tax return form?”… but you won’t need to worry when you have SimpleTax on your side.

Our online tax return software is designed to guide you through the submission process from start to finish, helping you catch up when you’re behind and prompting you about your tax responsibilities along the way. You can input figures at any time, and our system will do all the calculations for you.


Download the 14-day free trial and try SimpleTax right now completely free of charge. Don’t forget that you can get in touch at any time for support from our friendly team.

Trusted by over 20,000 subscribers

You don't need to be an expert to complete your self assessment tax return.

Find Out More

Blog content is for information purposes and over time may become outdated, although we do strive to keep it current. It's written to help you understand your Tax's and is not to be relied upon as professional accounting, tax and legal advice due to differences in everyone's circumstances. For additional help please contact our support team or HMRC.

5 Excellent Reasons to Choose Us

Discover how to make tax returns a doddle...

Find out more

Everything you need to know about payments on account

31 Mar 2024

The video explains payments on account for self-assessment in the UK, showing a live example on a tax return, discussing when and how they’re…

Implementation of Making Tax Digital

31 Mar 2024

The video explains the upcoming basis period reform, which will impact how businesses and the self-employed in the UK calculate their tax bill, aligning…

Changes to side hustles and how it impacts tax reporting

31 Mar 2024

HMRC is tightening its oversight by asking popular side hustle platforms such as Upwork, Fiverr, Airbnb, Etsy, and Uber to report taxpayer earnings directly…

How GoSimpleTax Works


Simply register for free with your full name and email address.

Select Your Income

Select the income you receive and follow the hints and tips for potential tax savings.

Validate Your Information

Validate your personal information and submit directly to HMRC to get confirmation in just seconds.


Work Anywhere, With Any Device

Gone are the days of fretting over a calculator surrounded by scraps of paper at the eleventh hour.

GoSimpleTax’s tax return software uses the information you upload in real time to calculate your income and expenditure, working out the tax you owe and sending you helpful notifications when there’s the possibility of a mistake.

Start your free trial

"The software is intuitive and proved very easy to navigate. I found the whole process refreshingly simple. I saved a lot of money too!"

Steve J.

Ordained Presbyter

"Easy to use and value for money. Everything you need to do your tax."

Gordon J.

Self Employed

"It fills in all the forms and sends them to the Inland Revenue. Not expensive either. Takes the stress out of doing your tax return online."

Ross G.

Team Rector

5 reasons to use GoSimpleTax >