6 tips to file your tax return by midnight and avoid a £100 fine

The final deadline for self-assessors to file their 2021-22 tax returns is midnight tonight – failing to do so could result in a £100 fine.

Last week, HMRC said it was still waiting for nearly 3.4 million people to file their returns. While many will have done so by now, there is often a last-minute surge on the final day.

While HMRC says it will be lenient towards anyone who has a genuine excuse for their tax return being late, last year saw almost 400,000 charged a penalty for not submitting their self-assessment on time, according to data from the Tax Policy Associates think tank. 

Remember, today is also the deadline for paying your tax bill to HMRC, and late payment interest is double what it was this time last year. It’s currently set at 6%, but because it’s linked to the Bank of England base rate, it could rise further in future.

Here, Which? reveals six tips to help you get your 2021-22 tax return submitted before the deadline.

1. Check your login details

If you’re filing your tax return on the government website, you will need your government gateway ID and password, so it’s best to have them handy to avoid any frustrating login delays.

Don’t worry if you have forgotten or lost these details – they can be reset. This can take some time, however, so it’s a good idea to test them out well ahead of the deadline, even if you’re not quite ready to file yet.

2. Have your paperwork ready

If you’re filing your tax return at the last minute, it can be easy to panic and make a silly mistake. But getting all the all relevant documents and information together before you start means you can focus on the task in hand, rather than scrabbling about looking for important details.

The most important documents you will need are your P60 form (if you’re employed), relevant receipts and invoices, bills, bank statements, tenancy agreements, student loan statements and details of any benefits. 

Crucially, you’ll also need your National Insurance number and Unique Taxpayer Reference (UTR) number. 

3. Don’t forget about allowances and expenses

You can reduce your tax bill by making full use of all the allowances and tax reliefs you’re eligible for. 

Business expenses, for example, can be deducted from your taxable income. These include business travel and transport, maintaining or replacing work uniforms, office running costs such as stationery or phone bills, and the cost of business premises (including energy bills) – all of them can count as an allowable expense.

Higher-rate or additional-rate taxpayers can also take advantage of tax relief on charitable donations, as well as tax relief on pension contributions. 

If you are declaring capital gains – through selling shares or an investment property, for example – you get an annual allowance before CGT is payable. You can also offset losses from the same or a previous tax year to reduce your bill. Just register the losses on your self-assessment form.

4. Remember to pay on time, too

Once you’ve filed your tax return, you’ll then need to pay any tax due to HMRC – and the deadline to settle the bill is also midnight tonight.

If you don’t pay on time, you’ll be charged daily interest from the date the payment was due and there may be further penalties if you’re several months late paying your tax bill. 

The quickest way to pay your self-assessment bill is via the free HMRC app. The app can also help with information such as your UTR number, National Insurance number, tax credit payments and any PAYE information. 

If you think you’re going to struggle paying the bill on time, get in touch with HMRC as soon as possible to discuss your options. 

If you owe less than £30,000 in tax, you may be able to sign up for the Time to Pay arrangement. This allows you to pay in smaller instalments, but you’ll still be charged interest on what you owe.

5. Check for accuracy before pressing send

Before submitting your tax return, take a few minutes to review the information and make sure it’s accurate. 

HMRC can impose fines for mistakes if it thinks you haven’t taken ‘reasonable care’ in filling out the form. Penalties are based on the amount of tax you owe, and whether HMRC believes you have provided incorrect information on purpose. Charges for errors are calculated as below:

If you’re missing certain figures or information, you can submit estimates that you can come back and update later – just make it clear when you submit the form. It’s better to submit estimated figures than miss the filing deadline.

6. Try the Which? tax calculator

The Which? tax calculator not only helps you tot up the tax you owe, it can also suggest expenses and allowances you might have forgotten. 

Plus, when you’ve finished filling out your information, you can also use the tool to submit your tax return directly to HMRC.