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Tax Advice

How To Do A Tax Return In The UK

Learn the essentials of completing a UK tax return.

How To Do A Tax Return In The UK

Filing a tax return for the first time might sound tricky, but it doesn’t have to be.

Whether you’re self-employed in Belfast, earn rental income, or have investments, this guide will help you feel confident about completing your tax return.

What is a tax return, and who needs to file one?

What is a tax return?

A tax return is a form that tells HMRC (the UK government tax office) how much money you made in a year. You also include information about expenses, tax reliefs, and other deductions, so HMRC can figure out how much tax you owe - or if they owe you money (that would be nice for a change)!

Who needs to file a tax return?

You need to file a tax return if:

  • You’re self-employed (e.g., a freelancer, consultant, or small business owner).
  • You made more than £2,500 in untaxed income after allowable expenses, or £10,000 before allowable expenses. An example of untaxed income is renting out a property.
  • You made money from savings, investments, or overseas income.
  • You want to claim tax relief (e.g., on donations or pensions).

For a full list, check HMRC’s website to see if you need to file a tax return.

Interactive tax return checklist

Do you need to file a tax return?

Use this quick checklist to help decide:

  • Did you make more than £12,570 this tax year?
  • Do you have untaxed income, like from renting out a property or freelance work?
  • Do you earn from savings, dividends, or investments?
  • Are you claiming tax relief (e.g., on donations)?

If you answered yes to any of these, you’ll likely need to file a tax return.

Confused about complex tax rules?

Professional tax advice can help you save money and avoid costly mistakes.

For a stress-free experience, we advise using our recommended provider.

Preparing for your tax return

How to register for self-assessment

If you’re filing for the first time, you’ll need to register for self-assessment with HMRC.

  • Go to the HMRC self-assessment registration page.
  • Create a Government Gateway account and provide details like your National Insurance number.
  • Once registered, HMRC will send you a Unique Taxpayer Reference (UTR) number by post. This is your unique code for all tax returns.

Registration deadline

Make sure to register by 5th October after the end of the tax year in which you started earning untaxed income.

Watch this video for a step-by-step guide on how to register if you’re self-employed.

What documents do you need for a tax return?

Before starting your tax return, you’ll need to gather important documents. Here’s a list of what to prepare:

Personal information

  • National Insurance number
  • Unique Taxpayer Reference (UTR)

Income records

  • Employment income. P60 form from your employer, or P45 if you changed jobs.
  • Self-employment income. Records of what you earned and spent.
  • Rental income. If you rent out property in Belfast, or anywhere else for that matter, make sure that you gather records of rent and any related expenses (like repairs).
  • Savings and investments. Bank statements showing interest earned or dividends received.
  • Pension income. Records of any state or private pension received.

Expense records

If you’re self-employed, you can claim expenses to reduce your tax bill. Common deductible expenses include:

  • Office supplies, travel, and any business-related purchases.
  • Keep receipts to back up your claims!

Different filing scenarios

Self-employed freelancer

If you’re a freelancer, you’ll need to report all your earnings from clients, minus any expenses like travel costs or software. You can also claim tax relief on business expenses.

Landlord

For landlords, you’ll report rental income and expenses like maintenance, repairs, and property management fees. This reduces your taxable income.

Investors

If you make money from investments, such as dividends or capital gains, you’ll need to declare them and possibly pay capital gains tax.

High earners

If you earn over £150,000, even if it’s through a regular job, you’ll need to file a return. You’ll also likely pay additional tax.

Side hustles

If you run a side hustle (e.g., selling things online, or freelance work), you need to report this income even if it’s part-time.

Expats

If you’re an expat with foreign income, you may need to declare it in the UK, especially if it wasn’t taxed abroad.

Filing your tax return in Belfast

Filling out your tax return can be done online or by paper, though most people prefer the online option.

Step-by-step guide for online filing

  1. Log in to your HMRC account using your Government Gateway details.
  2. Start your self-assessment. Choose “File Tax Return.”
  3. Input personal details. Fill in your National Insurance number, UTR, and other personal info.
  4. Declare your income. Report all your earnings - employment, self-employment, savings, rental, etc.
  5. Claim expenses. If you’re self-employed, list your allowable expenses.
  6. Check for tax reliefs. Include any tax reliefs or allowances (e.g., for charitable donations).
  7. Submit. Review your return and hit submit.

Deadlines

  • Paper return deadline. 31st October
  • Online return deadline. 31st January

Common issues when filing a UK tax return

Here’s what to do if you run into problems:

Error messages

If you see an error while filing online, clear your cache or try again later. If the problem persists, contact HMRC support.

Forgotten UTR

If you’ve misplaced your UTR, log into your HMRC account to find it, or check any letters HMRC has sent you.

Incorrect information filed

If you realise you made a mistake, you can amend your return within 12 months of the original deadline.

Consider filing early to avoid stress

Filing early can save you a lot of stress. Here’s why:

  • Avoid the rush. If you file early, you avoid the last-minute panic. Accountants in Belfast are very busy during tax season, so you will typically get faster responses if you file early.
  • Get your refund sooner. If HMRC owes you money, filing early means you get it back faster.
  • Avoid penalties. If you file early, you don’t have to worry about missing the deadline and being fined.

What to do if you can’t afford your tax bill

If your tax bill is higher than expected and you can’t afford to pay it all at once, you can set up an HMRC payment plan.

Time to Pay arrangement

With a Time to Pay plan, you can spread your payments out over time. Just contact HMRC, and they’ll help set up a manageable payment schedule.

What happens if you don’t file your tax return on time?

Penalties for late filing

  • £100 fine if you’re up to 3 months late.
  • More fines if you continue delaying.
  • Interest charges on any tax owed after the 31st January payment deadline.

How to get money back from HMRC

Did you know you might be owed a refund? Here’s how to claim one:

Overpayments

If you’ve paid too much tax (like through employment), you can get a tax refund. Keep records of any employment expenses you’ve claimed.

How to claim a refund

Once HMRC reviews your return, they’ll calculate if you’re due a refund. Refunds normally arrive within 5-10 business days if you filed online, but can take as long as 10 weeks.

Local charities in Belfast

Supporting local charities not only benefits your community but can also reduce your tax bill. When you donate to UK registered charities, you can take advantage of Gift Aid, boosting your donation by 25% at no extra cost. If you’re a higher or additional rate taxpayer, you could also claim tax relief on your donation.

Explore these amazing charities in Belfast and consider giving back today.

The Royal Irish Regiment Charity
To preserve in perpetuity the Regiment Memorials and Chapels,To Make grants to any other charitable organisation for the benefit of the Regiment and to run the resources of the charity effectively,To relieve either generally or individually persons who are past or present members of the Regiment or former members of the former regiments and the dependants of such persons who are in need
Royal Irish Regimental Charity, 28 Bedford Street, Belfast, BT2 7FE
07311 325744
Charity Number: 1052056
Date Registered: 16 January 1996
Income: £648,689 (March 2023)
2k Plus International Sports Media
Reporting on sport, for the fans, with a Christian perspective through radio, social media and live exhibitions. We produce a weekly 30-minute radio programme, Planet Sport Football Africa, broadcast on over 45 radio stations in Africa, North America and the UK. Our live exhibitions, Sports Stories Spaces, showcase the stories of Christian athletes in host cities during major sports events.
Passion For Sport, 218 York Street, Belfast, BT15 1GY
07425 688524
Charity Number: 1091941
Date Registered: 9 May 2002
Income: £54,071 (March 2022)
Diabetic Pregnancy Study Group
The aims of the Diabetic Pregnancy Study Group (DPSG) are to improve the detection and management of diabetes in pregnant women and their offspring through education, teaching and research. Obesity before and during pregnancy has recently been added to the DPSG portfolio. The DPSG is affiliated to the European Association for the Study of Diabetes (EASD).
Royal Victoria Hospital, Grosvenor Road, Belfast, BT12 6BA
02890633430
Charity Number: 1175906
Date Registered: 23 November 2017
Income: £9,217 (August 2022)
Biblica Europe Ministries Trust
Biblica is a worldwide organisation focusing on 3 core strategies of Bible translation, Bible Publishing and Bible Engagement. The mission statement is "transforming lives through God's word". The charity concentrates on carrying out these objectives in the UK and Continental Europe and also operates in other countries as included in A12 above.
The Mount Business Centre Ltd, 2 Woodstock Link, Belfast, BT6 8DD
02890735875
Charity Number: 227111
Date Registered: 29 October 1963
Income: £1,968,991 (September 2023)
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Final thoughts

Filing a tax return might seem overwhelming, but by following these steps, you’ll be able to handle it with confidence.

About the author

Jon Dell is a Chartered Accountant who qualified at PwC, the largest professional services firm in the world. He has worked internationally as well as across public and private sectors. He now has his own practice where he provides both personal and limited company taxation services, management accounts, SEIS/EIS applications, bookkeeping, and payroll services. Contact Jon for a free quote: hello@jdell.co.uk.

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