Tips on How to Complete Your Tax Return

20th May 2020 / Sally Marshall / No Comments

Now we are well into another tax year, thousands of people are now doing the dreaded task of completing their Self Assessment tax returns.

Below I will outline 5 common mistakes people make on their tax returns, so you can avoid making these yourself and ensure that the correct amount of tax ends up getting paid to HM Revenue & Customs (HMRC) and that you are as tax efficient as possible:  

1)     Not declaring all the income you received in the tax year

It is important to include all the income you earn during the tax year, be it employment, self-employment, savings, dividends, rental properties, life assurance gains, overseas income and much more.

People often miss off supplementary pieces of income such as dividends, but it is important for everything to be included as HMRC are easily able to spot any anomalies.

That said there are some types of income which are exempt and do not need to be declared, such as income within an ISA or dividends from Venture Capital Trusts, provided the contribution/investment limits are adhered to.

2)     Not claiming eligible pension reliefs

Mistakes are often made when it comes to pension contributions, which can potentially be a complex area when it comes to maximising your tax relief.

You can make contributions either through your employment (most people do under auto-enrolment) or through private pension contributions.

In respect of making contributions through your employment, if you are making contributions under a ‘net pay scheme’ then you will have received your tax relief up front. If you are making contributions under a ‘relief at source’ arrangement, you obtain basic rate (20%) tax relief up front, but if you are a higher or additional rate taxpayer, you can claim additional relief through your tax return.

For further information regarding the tax relief on pension contributions, read our article.

3)     Not including expenses that can be claimed

If you are self-employed, your business will have various running costs. You can deduct some of these costs to work out your taxable profit as long as they’re allowable expenses. Typical expenses include office costs, travel costs, staff, advertising, financial costs and many more.

For more information regarding tax deduction for working from home, read our article.

The same goes for claiming expenses in relation to a property you rent out. Common types of rental expenses include general maintenance and repairs, insurance, letting agents fee, costs of services and many more.

For more information on tax deductions for rental properties, read our article.

4)     Including expenses that cannot be claimed

In order for expenses to be deductible from either self-employed income or rental income, the expenses must be ‘wholly and exclusively’ for the purposes of the trade or rental of the property. These must be proven as such in the event of HMRC raising an enquiry.

Areas where HMRC is most likely to scrutinise include legal and professional expenses, repairs and renewals, entertaining and stock. 

In the event of an expense relating to something used partly for business and partly for personal use, the allowable expense included in your return must be apportioned, for example if a computer was used 50% for business purposes and 50% for personal use, half of the computer costs are allowable.

In addition, the expenses must also be revenue, rather than capital expenses. This essentially means that there is not an ‘enduring benefit’ to that expense. An example of capital expenditure is purchasing a new car, van, or equipment. In the case of capital expenditure, there are separate rules on claiming the cost of these against your profits. These are known as the capital allowances rules.

5)     Not being aware of payments on account

As well as the tax that is due for the return you are submitting, HMRC may request making tax payments in advance of next year’s tax bill (depending on your circumstances) – this is known as a payment on account.

50% of the payment in advance is due by 31 January along with this year’s payment, and the other 50% is due by 31 July.

Please note that the 31 July 2020 payment on account does not need to be made. This is one of the government’s Covid-19 measures that have been put in place.

If your balancing tax liability is under £1,000, payments on account will not apply in any case.

Contact Me

If you would like any further information on the above article, or need any help filing your Self-Assessment tax return, please contact me on 01892 576550, email or visit

Jack Sales – Owner & Director of TN Accountancy

Please note that the above is for general information only and does not constitute financial or tax advice. You should not rely on this information to make or refrain from making any decisions. You should always obtain independent professional advice in respect of your own situation.

Posted in

Leave a Comment

Your email address will not be published. Required fields are marked *

Sam Howard

In Conversation with Sam Howard

Carrie Stay

In Conversation with Carrie Stay

Mike Greene

Summer Success: Navigating Work-Life Balance to Achieve Business Goals