Do I Need to Submit a Tax Return in the UK for 2026

Understanding whether you need to submit a tax return in the UK can save you time, stress, and potential penalties. The rules can seem complicated, but knowing the key criteria for the 2026 tax year will help you stay compliant and avoid unnecessary hassle. This guide breaks down who must file a tax return, when to do it, and what to expect.

Who Must Submit a Tax Return in the UK?

Not everyone in the UK needs to file a Self Assessment tax return. The government requires tax returns mainly from individuals with income or financial situations that HM Revenue & Customs (HMRC) cannot fully track through the Pay As You Earn (PAYE) system. Here are the main groups who must submit a tax return for 2026:

• Self-employed individuals earning more than £1,000 a year

• People with income from property, such as rental income

• Those with income over £100,000 per year

• Individuals with untaxed income, including dividends, interest, or foreign income

• Those who have capital gains to report, such as from selling property or shares

• Individuals with complex tax affairs that HMRC cannot assess automatically

  
  

If you fall into any of these categories, you will likely need to submit a tax return.

When Do You Need to Submit Your Tax Return?

The UK tax year runs from 6 April to 5 April the following year. For the 2026 tax year, this means income and gains from 6 April 2025 to 5 April 2026. The deadlines for submitting your tax return and paying any tax owed are:

• Paper tax returns: 31 October 2026

• Online tax returns: 31 January 2027

• Payment deadline: 31 January 2027

  
  

Filing online is the most common and convenient method. It also gives you extra time compared to paper returns. Missing these deadlines can result in penalties, so it is important to plan ahead.

How to Register for Self Assessment

If you have never submitted a tax return before, you must register with HMRC. You can do this online, and it usually takes a few weeks to receive your Unique Taxpayer Reference (UTR) number and set up your account. You should register by 5 October following the end of the tax year you need to file for. For example, if you need to file for the 2026 tax year, register by 5 October 2026.

What Information Do You Need to Complete Your Tax Return?

Gathering the right documents before you start will make the process smoother. Common information you will need includes:

• Your National Insurance number

• Details of your income from employment (P60 or P45 forms)

• Records of self-employment income and expenses

• Bank statements showing interest earned

• Dividend vouchers from shares

• Rental income and expenses

• Details of any capital gains, such as property sales

• Records of pension contributions and other tax reliefs

  
  

Keeping accurate records throughout the year helps avoid last-minute scrambling.

Examples of Who Needs to Submit a Tax Return

• Sarah runs a freelance graphic design business and earns £15,000 a year. She must submit a tax return to report her income and expenses.

• James receives rental income from a property he owns. Even though he has a full-time job, he needs to declare this additional income through Self Assessment.

• Emma earns £120,000 a year from her job. Because her income exceeds £100,000, she must file a tax return.

• Tom sells shares and makes a capital gain of £10,000. He needs to report this gain on a tax return.

  
  

What Happens If You Don’t Submit a Tax Return?

Failing to submit your tax return on time can lead to penalties starting at £100, even if you owe no tax. Additional fines increase if the delay continues, and interest may be charged on unpaid tax.

Do You Need Help With Your Tax Return?

Tax returns can feel confusing, especially if your situation has changed or you’re new to self-employment.

At LCM Accountancy, we help individuals and small businesses in Easterhouse and the surrounding areas with simple, stress-free tax returns.

We’ll make sure everything is accurate, submitted on time, and that you’re not paying more tax than you need to.

👉 Contact us today for a free, no-obligation chat.

Final Thoughts

If you’re unsure whether you need to submit a tax return in the UK, it’s always better to check early rather than risk penalties later.

Getting the right advice can save you time, stress, and money.

Need advice? Get in touch with LCM Accountancy today and we’ll be happy to help.