Meet the Self Assessment filing deadline with these top tips

The deadline for submitting a Self Assessment tax return online is midnight on 31 January each year. If you’re worried about missing the deadline, firstly, don’t panic. The good news is that there are ways to prepare, and if you miss the deadline, you have options.

In this article, we explain what you can do if you’re at risk of missing the Self Assessment deadline and if your tax return is overdue. We also discuss the penalties that apply when you miss the deadline and are unable to pay your tax bill on time.

If the Self Assessment deadline is approaching and you’re worried you won’t make the cut, there are things you can do to ensure you meet the deadline. Excellent time management and support from others are key. Here are some tips to consider:

1. Set some time aside 

Now’s the time to prioritise your Self Assessment tax return. Stay calm and find some time in your diary to focus solely on filling out and submitting your return.

You’re likely to be busy and tight for time, so consider delegating tasks to colleagues or employees where possible. Book out focus time in your diary and make sure you find a quiet place, free from distractions.

2. Use online tools

There are endless online resources that can help you with your Self Assessment. You can: 

• Use the HMRC forms and help sheets for guidance on each section within the SA100 form  
• Watch 1st Formations YouTube videos on everything from Self Assessment registration to tax bills and penalties 
• Read the 1st Formations blog and watch out for our monthly newsletter to get timely updates on key dates, deadlines, and Self Assessment advice 
• Read Self Assessment forums to learn from others, ask questions, and find guidance 
• Contact HMRC if you need extra support 

3. Get professional help

If you’re struggling to find the time to prepare your tax return on time, it could be worth seeking the help of a certified tax accountant. While the initial cost may seem high, it is worth it to avoid HMRC’s late filing penalty for Self Assessment.

Self Assessment dates for your diary 

The Self Assessment filing deadline and payment dates are the same every year. They fall after the end of the tax year, so you always have several months to prepare your tax return and pay any tax that you owe.

The tax year runs from 6 April in one year until 5 April in the following year.

A simple way to ensure you don’t miss the filing deadline is to set up automatic reminders. Add the final deadline of 31 January to your calendar and create a notification a month or so (or longer) in advance.

It’s also a good idea to repeat these reminders in the run-up to the deadline (i.e. a month before, two weeks before, one week before, etc.). We’ve made this step easier for you–simply click the button below to add the Self Assessment deadline to your calendar straight away.

Don’t forget about your payment on account deadlines. The first one falls on 31 January and the second on 31 July. Click the button below to add these reminders to your calendar, too.

Also, lots of people get caught out by payments on account, so ensure you put enough money aside each month to cover your tax bill. For more information on what it is, how it works, and how to reduce your payments, see our blog on ‘How to reduce your Self Assessment payments on account.’ 

If you’d rather not set up a Budget Payment Plan with HMRC, consider putting the money in a high-interest savings account, ready to use when it’s time to pay your Self Assessment bill. 

How to file a Self Assessment tax return

Missing an important deadline is always unfortunate, but try not to panic. The best thing to do is file your tax return as soon as you can. There are three ways to do this:

1. Online

The quickest and easiest way to submit your Self Assessment tax return is online. You’re also less likely to make a mistake in your submission this way.

There is no need to contact HMRC before doing so—simply file the SA100 form as you normally would. If this is your first time sending a Self Assessment tax return to HMRC, you may find the following guides helpful:

• How to register for Self Assessment
• Do I need an accountant to do my Self Assessment tax return?
• The top 10 Self Assessment tax return mistakes – and how to avoid them
• 12 Self Assessment expenses you didn’t know you could claim

Remember that you need to be registered for Self Assessment before you can file your first tax return. The registration deadline is 5 October (almost 4 months before the tax return is due). If you register after this date, a ‘failure to notify’ penalty may apply if you also deliver your tax return late.

2. By post

If you normally send your Self Assessment tax return by post but miss the filing deadline of 31 October, you still have an extra 3 months to file it online before it is deemed late. Paper tax returns are only due earlier because it takes HMRC more time to process them than online returns.

As long as you submit it online on or before 31 January, you won’t have to pay a late filing penalty. However, HMRC will apply the standard penalties if you file the late tax return on paper after 31 October.

3. Automatic filings through your tax code

If you would like HMRC to automatically collect your Self Assessment tax through your PAYE tax code, you must submit your online tax return on or before 30 December rather than 31 January.

If you are a non-resident company or a trustee of a registered pension scheme, you must send a paper tax return on or before 31 January (3 months after the standard Self Assessment filing deadline for paper returns). You cannot send an online return.

Self Assessment late filing penalties

Unfortunately, you will have to pay a late filing penalty of £100 if your Self Assessment tax return is up to 3 months late. Further charges will apply if it is even later.

HMRC will also charge penalties and interest if you fail to pay your tax bill on time. The payment deadline is midnight on 31 January—exactly the same as the online filing deadline.

You can use HMRC’s online calculator to estimate your penalties for missing the Self Assessment filing deadline or paying your tax late. However, it won’t take into account any of the following: 

• Payments that you have made toward your tax bill 
• Outstanding interest or penalties for earlier tax years 
• Any credit you have from previous tax years 

If you have a reasonable excuse for why your tax return (or payments) was late, you can make an appeal against a Self Assessment penalty. A reasonable excuse is something that prevented you from meeting tax obligations that you took reasonable care to meet, such as:

• Your spouse, partner, or another close relative passed away shortly before the filing or payment deadline 
• You had a serious or life-threatening illness or an unexpected stay in hospital 
• Your computer or software failed shortly before or while you were preparing your online tax return 
• There were service issues with HMRC online services 
• A fire, flood, or theft prevented you from completing the tax return 
• Unexpected postal delays 
• Delays related to a mental illness or disability that you have 
• You misunderstood or were unaware of your legal obligation 
• You relied on someone else (e.g. an accountant) to file your return, but they failed to do so 

You must send your overdue tax return and pay any outstanding tax as soon as possible after your reasonable excuse. Find out where to send your Self Assessment penalty appeal by going to the HMRC website.

How you appeal a penalty depends on whether it applies to an individual tax return or a Partnership Tax Return. Appeal online or use form SA370 if you are an individual. If you are a partnership, use form SA371.

You will need to provide the following details on the form: 

• Name and address 
• Unique Taxpayer Reference (UTR) 
• The date on which HMRC issued the penalty 
• The date on which you filed the tax return 
• Penalty (or penalties) you want to appeal against 
• Your reason for making an appeal 

Make sure you have submitted the tax return before making an appeal. HMRC may be unable to progress with your appeal until you do this.

If your appeal is upheld and you don’t have any outstanding tax to pay, HMRC will refund the penalties you’ve paid, including interest.

If you can’t pay your Self Assessment tax bill

You may be able to set up a payment plan with HMRC if you’re unable to pay your tax bill on time. This is called Time to Pay. The payment plan allows you to spread the cost of your latest Self Assessment bill over several months, giving you more time to pay and get back on track.

You can set up a payment plan online if all the following apply:

• You owe £30,000 or less 
• You don’t have any other payment plans or debts with HMRC 
• You’ve filed your latest Self Assessment tax return 
• It is less than 60 days since the payment deadline passed

You can choose how much you would like to pay immediately (if you can afford to do so) and how much you’d like to pay each month. To set up a payment plan, you will need:

• Your Unique Taxpayer Reference (UTR) 
• Your UK bank account details (to set up a monthly Direct Debit with HMRC) 
• Details of any previous payments that you have missed 
• Details of your income and spending (to work out how much you can reasonably afford to pay each month)

For more information, see our blog on ‘HMRC’s Time to Pay Scheme for Self Assessment customers’. 

If you can’t set up a payment plan online 

You will need to contact HMRC directly if you are unable to set up a payment plan online for any reason. They will ask you for the following information: 

• Why you are unable to pay your tax bill
• How much you can afford to repay each month 
• If you have any other taxes to pay 
• How much money you earn
• Your monthly outgoings
• Whether or not you have any savings or investments

If you have savings or assets, HMRC would normally expect you to use these to pay as much of your tax bill as possible.

If you have taken independent debt advice (e.g. from Citizens Advice or StepChange), you may have a ‘Standard Financial Statement’. HMRC will accept this statement as evidence of your monthly earnings and personal expenses.

Once you have paid all the tax you owe, you should consider setting up a Budget Payment Plan with HMRC to make regular weekly or monthly payments toward your next Self Assessment tax bill.

Is late filing information shared publicly?

HMRC will not publicly disclose any information about your Self Assessment tax returns or bills. You do not have to worry about clients, lenders, credit reference agencies, or anyone else finding out, so it should not impact your personal or business reputation.

Will my tax debt affect my credit score?

Owing a debt to HMRC, whether for tax or penalties, has no effect on your personal credit score. The reason for this is simple: HMRC has not given you credit. Yes, you may owe money to the government, but you didn’t borrow it from them.

For this reason, any debts you owe to HMRC won’t negatively impact your financial health or reduce your chance of obtaining credit. However, if these debts remain outstanding and you do not engage with HMRC or attempt to pay what you owe, the outcome may be very different.

Under such circumstances, HMRC may: 

• Use a debt collection agency to settle your debt 
• Directly recover your tax debts from your wages or any monthly pension payments you receive 
• Take things that you own and sell them (unless you live in Scotland) 
• Take money directly from your bank account or building society savings (unless you live in Scotland) 
• Take you to court 
• Start bankruptcy proceedings 

As long as you contact HMRC as soon as possible and try to come to an arrangement, you shouldn’t have to worry about any of the above scenarios. HMRC will only use its tax debt enforcement powers where a person or business deliberately avoids paying their tax bills.

Get ready to meet your Self Assessment filing deadline

Keeping track of your tax obligations is challenging, especially when you’re short on time. Thankfully, you can avoid this and any added stress from Self Assessment filing penalties by following the top tips in this blog.

Remember, if you are within 3 months of the most recent online filing deadline, try to send your tax return as quickly as possible. This will help you avoid further charges on top of the £100 automatic penalty. If your tax bill payment is also late and you are struggling financially, set up a payment plan with HMRC.

Remember, it may be worth seeking specialist advice if you need help filing your tax return on time. Please also feel free to leave a comment below if you have any questions about this post.